TEXT: UNDERMOUNTAIN
  THE LOST CHAMBERS
  Phil Beckwith, Alex Clippinger, Elise Cretel, Ashley May, 
  Luciella Scarlett, Christopher Walz & Micah Watt
  
  1
  Publisher: Pyromaniac Press
  Authors: Phil Beckwith, Alex Clippinger, Elise Cretel, 
  Ashley May, Luciella Scarlett, Christopher Walz & Micah Watt
  Layout: Micah Watt
  Editor: R. P. Davis 
  Cover Art: Dean Spencer
  Internal Art: Dante Cifaldi, Luciella Scarlett, Dean Spencer, 
  Luigi Castellani, Fesbra, Daniel Comerci - daniel comerci.com, 
  DMsGuild Creator Resource (Varied)
  Cartography: Phil Beckwith, Chris Bissette
  Backgrounds: Dante Cifaldi
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  UNDERMOUNTAIN
  The Lost Chambers
  
  2
  Table of Contents
  Level 
          Page
            3
      3 
            4
      6 
           11
  Adventure 
  Introduction 
  Abandoned Atelier 
  Maestro's Hideout 
  Sanctuary of the Goddess 
      6 
           18
  UWPS (Undermountain Water Purification & Sanitation)    6 
           24
  Keeper of Secrets 
      7 
           29
  Mouthers of Madness 
      8 
           35
  Of Two Minds 
      8 
           40
  Hunger of Abbathor 
      9 
           50
  Molthglor's Garden 
     12 
           58
  Sargauth Sanctuary  
     12 
           63
  Cathedral of Bones  
     13 
  Author 
  Ashley May  
  Elise Cretel  
  Elise Cretel  
  Alex Clippinger 
  Micah Watt  
  Alex Clippinger 
  Christopher Walz 
  Micah Watt  
  Phil Beckwith 
  Luciella Scarlett 
  Christopher Walz 
           70
  Author Biographies 
           77
  
  3
  Introduction
  Welcome to Undermountain: The Lost Chambers!
  This compilation of 11 adventures, brought to you by 
  seven of the Dungeon Masters Guild's best authors, is 
  intended to be a modular set of adventure locations 
  designed to be dropped into any location within 
  Undermountain with little to no effort on your part to 
  integrate them.
  They are intended for use with the Dungeon of the Mad 
  Mage hardcover, but could easily be introduced as part 
  of any Undermountain or dungeoncrawl campaign.
  Undermountain: The Lost Chambers has some internal 
  continuity, but each of the locations can be used as self-
  contained encounters, each with unique features and 
  NPCs, to add depth and detail to your journey through 
  the vast, dark halls of the Mad Mage.
  Substance and Style
  Upon first read through you will notice that there is 
  variation in the presentation of the adventure locations 
  from author to author. For example, some make use of 
  read-aloud text while others do not. Some have a sword 
  & sorcery/OSR influence, while others are more high 
  fantasy, comedic or even a grittier flavor. 
  This is not a mistake. This is an effort to ensure that your 
  favorite authors remain true to their unique style as they 
  contribute to this compilation. Continuity is maintained 
  through layout consistency, but as each author brings 
  a unique voice to the project, we wanted to honor that 
  by letting each write the way they are most comfortable 
  with.
  The result is a compilation that reflects the contributors. 
  Some readers may find that this makes various 
  adventures perhaps more or less compelling, but we're 
  sure that you will find material to your tastes within 
  Undermountain: the Lost Chambers.        
            
   
  Adjusting the Adventures
  In addition to indicating the appropriate character level 
  for play, some of these adventures provide suggestions 
  in making adjustments for smaller or larger groups, 
  characters of higher or lower levels, and characters that 
  are otherwise a bit more powerful than the adventure is 
  optimized for. You’re not bound to these adjustments; 
  they’re here for your convenience.
   
  To figure out whether you should consider adjusting the 
  adventure, add up the total levels of all the characters and 
  divide the total by the number of characters (rounding 
  .5 or greater up; .4 or less down). This is the group’s 
  Average Party Level (APL). To approximate the party 
  strength for the adventure, consult the following table.
  Determining Party Strength
  Party Composition  
   
   
  Party Strength
  3-4 characters, APL less than 
            
  Very weak
  3-4 characters, APL equivalent 
   
  Weak
  3-4 characters, APL greater than  
    
  Average
  5 characters, APL less than  
   
  Weak
  5 characters, APL equivalent  
   
  Average
  5 characters, APL greater than  
   
  Strong
  6-7 characters, APL less than  
   
  Average
  6-7 characters, APL equivalent  
   
  Strong
  6-7 characters, APL greater than  
   
  Very Strong
  Some encounters may include a sidebar that offers 
  suggestions for certain party strengths. If a particular 
  recommendation is not offered, or not appropriate for 
  your group, you don’t have to make adjustments.
  Acronyms Used
  PHB - Players Handbook
  DMG - Dungeon Masters Guide
  MM - Monster Manual
  VGTM - Volo's Guide to Monsters
  MToF - Mordenkainen's Tome of Foes
  
  4
  Abandoned Atelier
  The adventure location is designed for 4-6 characters of 
  level 3 (Tier 1, APL 3).
  Adventure Background
  Between the mad wizard and his mad apprentices, no one 
  can be entirely sure who is to blame for the construction 
  of this alchemical laboratory, or who eventually left so 
  much valuable knowledge and equipment to decay.  At 
  the heart of the abandoned atelier lies a hidden garden 
  that was once used for the controlled growth of special 
  plants and mushrooms.  Over time, a combination of 
  curiosity, madness, and perhaps an interest in Zuggtmoy, 
  the Demon Queen of Fungi (see Adventure Hooks), led 
  them down the path that eventually led to the ruin of this 
  lab.
  A parasitic fungus deep within the atelier’s underground 
  garden mutated and infected a colony of otherwise 
  peaceful myconids that lived in the neighboring caves.  
  By hijacking the rapport spores the myconids use to 
  communicate, the parasitic fungus quickly took over the 
  entire colony of myconids, turning them into mindless 
  followers that exist only to tend to the growth and 
  continued survival of the stationary parasite.
     
  Adventure Overview
  The characters enter the abandoned atelier by clearing 
  some light, moss-covered rubble that blocks its entrance.  
  The entrance is noticed in passing by a dim, blue-green 
  glow coming from the other side of the debris.
  In exploring the abandoned atelier, they find a variety of 
  bizarre, overgrown fungi have consumed the dark and 
  damp space.
  The goal is to flip three gold-handled levers in the upper, 
  middle, and lower studies, granting access to the hidden 
  garden and the final boss.
  Adventure Hooks
  Strange Goings-On. A "zombie myconid" was spotted 
  in a cave closer to the surface, or even on the surface at 
  night.  It was behaving strangely, and attacked someone 
  (a miner, a traveling merchant, a farmer, etc).  The 
  adventurers are asked by a local researcher to look into 
  the bizarre occurrence.
  Look, A Suspicious Rock Pile! The adventurers stumble 
  on the Abandoned Atelier as part of their wanderings 
  through the halls of Undermountain.
  Not Her Again… If your party has played Rage Of Demons 
  storyline, they’ve likely already become acquainted with 
  Zuggtmoy, the Demon Queen Of Fungi.  Her influence 
  can be easily woven into this dungeon via symbols of 
  worship and motifs etched in stone or on book covers.  
  This isn’t necessary for the narrative, but can be a fun tie-
  in for a party that will recognize the references.
  Suggested Treasure
  There are some minor treasures provided in the dungeon, 
  but besides a few scrolls and potions, they are generally 
  items pertaining to the dungeon itself and will be of 
  limited use in later adventures.
  The theme of the dungeon is very plant-like, but at its core, 
  it is a long-abandoned atelier once used by an alchemist. 
  For this reason, it could have any number of items and 
  equipment of interest to adventurers.  You may use this 
  as an opportunity to distribute items that will benefit your 
  particular party at your discretion.
  General Features
  Terrain. The entirety of the alchemy lab is worked stone 
  block.  The stone itself remains in relatively good condition, 
  but much of it is faintly slickened by a thin sheen of algae 
  flourishing in the humidity.
  Light. Most rooms have very little light.  There are numerous 
  bioluminescent plant growths, but none cast enough of an 
  ambient glow to even provide dim light.
  Odor. The atelier carries a musty scent of stagnant air and 
  mold.  The humidity is almost oppressive.  
  
  5
  1a. Library Hall, Upper
  Stairs lead downward to another landing before 
  doubling back.  If a light source is tossed from the 
  uppermost landing, it clatters down the stairs and falls 20 
  feet before landing on the moist floor below, illuminating 
  a ruined laboratory.
  From the upper landing, there is a large wooden double-
  door to the west.  From the lower landing, there is a large 
  wooden double-door leading to the east.
  The Doors. The doors are all secured, likely barred 
  from the other side, as there are no visible locking 
  mechanisms.  However, the rotten wood can easily be 
  broken and the doors can be broken through with a DC 
  10 Strength (Athletics) check.  A knock spell will also 
  unseal the doors.
  The Bookshelves. The humid air has not been kind to 
  the library here, and the books are nearly all rotted and 
  destroyed.  Various fungi grow from the parchments and 
  leather book bindings, and the ink within has run to the 
  point of illegibility.  Each 5-foot section of bookshelf has a 
  5% chance of finding something noteworthy.
  Roll 1d4   Treasure
       1 
      A rare tome worth 20gp
       2 
      A hollowed-out book hiding gems (DM’s 
   
      discretion)
       3 
      spell scroll, cantrip (DM’s discretion)
       4 
      spell scroll, 1st level (DM’s discretion)
  1a. Library Hall, Lower
  Descending the stairs past the middle landing, the 
  party enters the ruined lab.  There is a set of wooden 
  double doors on the western wall.  There is also a larger 
  door here, on the southern wall, that is made of solid 
  stone.  There are no visible key holes, and the locking 
  mechanism is too complex for a knock spell to provide 
  any benefit.
  Heaps of rotten books lay against the walls, fallen from 
  the bookshelves that line the stairs above, and a broken 
  ladder lies across the floor.
  2. The Upper Study
  Entering the uppermost door on the western landing 
  presents the party with a dark and eerie room, in which 
  surfaces faintly glow with bioluminescent fungal growths. 
  If the party progresses into the room with a bright light 
  source, they risk triggering several shriekers growing 
  around the room, as well as the room’s possessed 
  myconids and a singular gas spore on the far side of the 
  room, guarding a gold-handled lever on the wall.
  Creatures. Four shriekers (MM p138) are scattered 
  around the room.  Five possessed myconids (see 
  Appendix) and a gas spore (MM p138) are present at the 
  far end of the room.  Remember that the gas spore appears 
  You stand on the landing at the top of a flight of stairs 
  leading downward into darkness.  Every wall around 
  you, every conceivable vertical surface, is embedded with 
  bookshelves.  The stairs below your feet are unremarkable, 
  but the ceiling is a stunning sight to behold.
  Above your head is an upside-down forest of fungal 
  growths.  Fuzzy, curling stalks extend downward from the 
  ceiling some ten feet above your heads, emitting soft glows 
  in blues and greens.  Water droplets seep through the stone 
  blocks above, catching the light as they drip down before 
  falling into darkness.
  Your feet make wet sounds each time they unstick from 
  the algae-slickened stairs, descending further and further 
  until you finally reach the bottom of the tall room.  A quarter 
  inch of stagnant water has pooled on the floor.
  The focal point of the room is a grand desk made of dark 
  wood.  Once a model of craftsmanship and the woodcarver’s 
  art, the desk is now half-collapsed from rot. The glass 
  bottles on its surface are broken, the alchemy equipment 
  has rusted beyond repair, and the desk now hosts a variety 
  of fungi that have made the wet wood their home.
  On the southern wall, you can see the frame of a large 
  door, but rather than a set of wooden doors like you’ve seen 
  several times before in this place, there is a slab of smooth 
  stone.
  Beyond the-west facing door, and past the reach of your 
  light sources, is a dark room.  Wherever your light does not 
  reach as the door swings open, the surfaces glow faintly.
  
  6
  
  7
  to be a beholder (MM p28), and should be described as 
  such to the party, unless a character succeeds on a DC 15 
  Intelligence (Nature) check.
  Tactics. The shriekers mindlessly scream as long as 
  there is a bright light source nearby, but they are essentially 
  a harmless distraction.  The gas spore attempts to move 
  itself into the middle of the party so that its death burst 
  will effect as many creatures as possible.  The possessed 
  myconids try to attack the closest enemy to them, with 
  little concern for threat potential.  One of the possessed 
  myconids is armed with a gold-headed “club”, which does 
  1d4 bludgeoning damage.
  Treasure. On a successful DC 15 Intelligence 
  (Investigation) check to examine the club carried by one 
  of the possessed myconids, an adventurer realizes that 
  the club resembles the gold-handled lever on the wall.  
  The opposite end of the “club” has several notches and 
  grooves, somewhat like a round key.  It does not fit into 
  any devices in the current room, but will be necessary for 
  operating the device in Room 4, The Lower Study.  Note:  
  If the players make no attempt to investigate the club or 
  show no interest in it, you can turn the Investigation check 
  into a DC 15 Wisdom (Perception) check to “notice” the 
  same features.
  Development. If the party flips the lever at the other 
  end of the room, they will hear mechanical sounds echoing 
  through the walls, but no additional effects are apparent.
  3. The Middle Study
  Entering the eastern door on the middle landing will 
  place the party in a warm, dry room.  The ceilings are 
  roughly fifteen feet high, and the glowing ‘dandelion puffs’ 
  that hang above emit low light.  If the party attempts to 
  check the books, they’ll find that most are long-winded and 
  technical treatises on the influences of various schools of 
  magic on gardening.
  Creatures. Seven “dessicated myconids” are laying 
  around the room, and appear to be shriveled and lifeless 
  until they choose to take action.  They will be stirred to 
  attack the party once the party has fully entered the room, 
  and a creature approaches the lever on the wall.  These 
  dessicated myconids are functionally the same as the 
  possessed myconids used elsewhere in the dungeon, but 
  are vulnerable to fire damage. In addition, they regenerate 
  1d8 hp per turn if given access to water (water-based 
  attacks, stolen waterskins, etc).
  Tactics. The dessicated myconids are drawn to any 
  water source they can identify, and relentlessly pursue 
  visible water skins hanging on belts or backpacks.  If any 
  adventurer uses a water-based attack on them, they focus 
  their attacks on that adventurer.
  The clay jars on the desks are filled with one gallon of 
  water each.  Area-of-effect spells can damage the desks 
  Upon entering this room you feel a welcome reprieve 
  from the suffocating humidity of the stairwell.  In fact, by 
  comparison the dryness in this room is almost unsettling.  
  The room is dimly lit by large, lantern-like dandelion puffs, 
  which emit a faint fiery glow from under their fluffy surfaces.
  The bookshelves that wrap around the room seem 
  remarkably well preserved, and dust-covered alchemical 
  equipment lays on the desks along with some large, sealed 
  clay jars.  On the far side of the room, you can see a gold-
  handled lever in the wall.
  The floor here is littered with the desiccated remains of 
  what were once myconids, now shriveled and apparently 
  lifeless.
  
  8
  and cause the jars to break, providing the dessicated 
  myconids with a source of restoration.
  Development. The “dandelion puffs” that hang above 
  the room are in fact flammable and will violently combust 
  if struck, creating an explosion of fire in a 15-foot radius 
  around them.  A creature caught within the area must 
  make a DC 15 Dexterity saving throw, taking 14 (4d6) 
  fire damage on a failed save, or half as much damage on 
  a successful one. You can consider having missed ranged 
  weapon or spell attacks trigger the ‘puff’ explosions.  The 
  bookshelves and work tables in this room are highly 
  flammable due to the dryness.  The dessicated myconids 
  single-mindedly flee from exploding puffs.
  If the party flips the lever at the other end of the room, 
  they hear mechanical sounds echoing through the walls, 
  but no additional effects are apparent.
  4. The Lower Study
  Entering the western door at the bottom of the stairs 
  presents an old alchemy lab and potion storage.  A 
  convoluted brewing device consumes much of the far side 
  of the room, and a DC 15 Wisdom (Perception) check 
  reveals that liquid remains in some of the tubes and 
  suspended bottles.  Further examination of the liquid will 
  rely on a DC 15 Intelligence (Arcana) check to identify 
  that the liquid is likely acidic.
  The base of a lever, like those seen in previous rooms, is 
  mounted on the wall behind the brewing device, obscured 
  by the device and only noticed on a successful active or 
  passive DC 20 Wisdom (Perception) check.  However, 
  the arm of the lever is missing.  If a mundane object is 
  inserted into the device to function as a makeshift arm, 
  the lever does not budge, seemingly ‘locked’ in place.  It 
  requires the use of the lever arm from the Upper Study 
  to unlock it. Alternately, a lever can be unscrewed from a 
  previous room and inserted into the mechanism to move 
  it.
  The brewing device is immovable, as various sections are 
  bolted to the stone base.  Sections may be disassembled 
  to allow access to the lever socket beyond the device with 
  a DC 15 Intelligence (Arcana) check.  An adventurer 
  proficient in alchemist’s supplies has advantage on this 
  check.  On a failure, pieces of the glass apparatus break 
  and the creature attempting disassembly takes 5 (2d4) 
  acid damage.
  A Small creature can attempt to climb through the 
  device’s maze of tubes and bottles to access the lever base 
  with a successful DC 15 Dexterity (Acrobatics) check. 
  A Tiny creature can perform the same feat with a DC10 
  Dexterity (Acrobatics) check.  On a failure, pieces of the 
  glass will break and the creature attempting to traverse 
  the device takes 5 (2d4) acid damage.
  Treasure. Searching the shelves reveals that most of 
  the potions are clearly compromised, with fungi growing 
  through the corks, tangled plant masses growing inside 
  the liquid, etc.  Of all of the hundreds, if not thousands 
  of potions here, searching each shelf has a chance of 
  yielding an intact potion. Roll 1d100. On a result of 01-10, 
  the searcher finds a usable potion. Select a potion from 
  the following table, or roll to determine the result.
  Roll 1d10 
  Treasure
       1 
   
  elixir of health (DMG 168)
       2 
   
  potion of climbing (DMG 187)
       3  
   
  oil of slipperiness (DMG 184)
       4 
   
  potion of poison (DMG 188)
       5 
   
  potion of water breathing (DMG 188)
       6 
   
  potion of resistance - acid (DMG 188)
       7 
   
  potion of resistance - fire (DMG 188)
       8 
   
  potion of resistance - cold (DMG 188)
       9 
   
  potion of resistance - poison (DMG 188)
      10  
   
  potion of greater healing (DMG 188)
  Development. If the party successfully moves the 
  lever, they hear mechanical sounds echoing through the 
  walls.  If the levers in the upper and middle studies have 
  already been flipped, the party hears the sound of stone 
  grinding on stone as the slab in the main room slides back.
  The shelves of this room are covered in bottles of various 
  shapes and sizes.
  A large contraption sits on a stone platform against the 
  far wall, composed of bottles suspended over unlit burners, 
  spiraling glass tubes, valves, gauges, and other almost 
  needlessly-complex alchemical brewing devices.
  
  9
  5. The Accursed Garden
  Entering the sealed door on the southern wall brings 
  the party into an eerily beautiful space.
  A successful active or passive DC 20 Wisdom 
  (Perception) check notices there is a lever on the back 
  wall, covered in plant growth.
  Creatures. The focal point of the room is the luminous 
  growth (see page 10), the source of the parasitic spores 
  that overcame the myconids.  It is assisted by four 
  possessed myconids (see page 10) that blend into the 
  overgrowth in the corners of the room, and can only be 
  spotted by a DC 20 Wisdom (Perception) check before 
  they begin moving.
  The luminous growth and other threats in the room do 
  not become active more than half the party has entered 
  the room.
  Tactics. If the myconids in the corners 
  of the room are not noticed before they 
  become active, they receive a surprise 
  round.  They use this to try to put 
  themselves in a more advantageous 
  position (blocking the exit, etc). The 
  luminous growth is immobile, so the 
  possessed myconids attempt to cut off the 
  party’s retreat by getting between them and the 
  door, and try to herd the party toward the growth.
  If the luminous growth is dealt damage, the possessed 
  myconids screech as if in pain (though they don’t actually 
  take any damage).  If the luminous growth dies before 
  the possessed myconids have died, on its death they 
  remain hostile, but their regeneration feature will cease 
  to function.
  Treasure. Lying on the floor of a garden path is a stone 
  amulet on a chain, covered in mossy growth.  The amulet 
  depicts a skeletally thin but feminine face set against 
  the underside of a mushroom cap.  A successful DC15 
  Intelligence (Religion) check identifies the symbol as 
  Zuggtmoy, the Demon Queen of Fungi, and Lady of Rot 
  and Decay (MToF, p156).
  Development. If the lever is flipped, a grinding sound 
  echoes through the room, and the water flowing into the 
  fountains will slow to a halt.  This enrages the luminous 
  growth and the possessed myconids, who single-
  mindedly attempt to turn the lever back on, except to 
  attack any creature between themselves and the lever.
  This room is eerily beautiful.  Fresh water flows from 
  fountains on the wall into troughs that run through the garden, 
  nourishing the wildly overgrown plant life.  Shimmering 
  spores float in the air like fireflies, stirred gently by the rush of 
  air that came through the now open door.
  In the center of the room is a heap of tangled plant life, 
  coated in luminescent purple mold.  
  The heap seems to simply be an 
  overgrown pile of weeds, until it stirs 
  and opens a massive maw, filled with 
  tooth-like thorny protrusions.  in the 
  center of its amorphous ‘body.’  A high-
  pitched whistling sound issues from 
  deep within it, not unlike a leaf whistle, 
  and several myconids emerge from the 
  overgrown and shadowy corners of the 
  room, whistling in chorus with their 
  leader. 
  
  10
  Possessed Myconid
   Medium plant, lawful evil
  Armor Class 12 (natural armor)
  Hit Points 22 (4d8+4)
  Speed 20 ft.
  STR
  DEX
  CON
  INT
  WIS
  CHA
  10 (+0) 10 (+0) 12 (+1) 10 (+0) 13 (+1)
  7 (-2)
  Senses darkvision 120 ft., passive Perception 11
  Languages --
  Challenge 1/2 (100 XP)
  Sun Sickness. While in sunlight, the myconid has disadvan-
  tage on ability checks, attack rolls, and saving throws. The 
  myconid dies if it spends more than 1 hour in direct sunlight.
  Regeneration. The myconid regains 3 hit points at the start of 
  its turn.  If it takes fire or radiant damage, this trait doesn’t 
  function at the start of the myconid’s next turn.  The myco-
  nid only dies if it starts its turn with 0 hit points and doesn’t 
  regenerate.
  Actions
  Fist. Melee Weapon Attack: +2 to hit, reach 5ft., one target. Hit 
  5 (2d4) bludgeoning damage plus 5 (2d4) poison damage.
  Pacifying Spores (3/day). The myconid ejects spores at one 
  creature it can see within 5 feet of it. The target must succeed 
  on a DC 11 Constitution saving throw or be stunned for 1 
  minute. The target can repeat the saving throw at the end of 
  each of its turns, ending the effect on itself on a success.
  Luminous Growth
  Large plant, lawful evil
  Armor Class 15 (natural armor)
  Hit Points 136 (16d10+48)
  Speed 0 ft.
  STR
  DEX
  CON
  INT
  WIS
  CHA
  18 (+4)
  8 (-1)
  16 (+3) 10 (+0) 13 (+1)
  5 (-3)
  Senses darkvision 60 ft., passive Perception 10
  Languages Common
  Challenge 4 (1,100 XP)
  Sun Sickness. While in sunlight, the myconid has disadvan-
  tage on ability checks, attack rolls, and saving throws. The 
  myconid dies if it spends more than 1 hour in direct sunlight.
  Actions
  Multiattack. The luminous growth makes two slam attacks. 
  If both attacks hit a Medium or smaller target, the target is 
  grappled (escape DC 14), pulled closer, and the luminous 
  growth uses its Engulf on it.
  Slam. Melee Weapon Attack: +7 to hit, reach 10 ft., one target. 
  Hit: 13 (2d8 + 4) bludgeoning damage.
  Engulf. The luminous growth engulfs a Medium or smaller 
  creature grappled by it. The engulfed target is blinded, 
  restrained, and unable to breathe, and it must succeed on a 
  DC 14 Constitution saving throw at the start of each of the 
  growth’s turns or take 13 (2d8 + 4) bludgeoning damage. The 
  growth can have only one creature engulfed at a time.
  Pacifying Spores (3/day). The myconid ejects spores at one 
  creature it can see within 5 feet of it. The target must succeed 
  on a DC 11 Constitution saving throw or be stunned for 1 
  minute. The target can repeat the saving throw at the end of 
  each of its turns, ending the effect on itself on a success.
  
  11
  Maestro's Hideout
  The adventure location is designed for 4-6 characters of 
  level 6 (Tier 2, APL 6).
  Adventure Background
  Every day the City of Waterdeep has merchants filling 
  the harbors with ships as goods flow into the market 
  place from the far reaches of Faerun. People travel far 
  to see the vast Waterdeep markets, the glittering jewels, 
  mystic swords, and other treasures found by the bravest 
  of adventurers. 
  As the fiery sun begins to set on the city’s horizon, candles 
  and oil light the night markets and taverns begin to fill 
  with adventurers, merchants, and singing. Like any city, 
  the City of Splendors is full of rumors of hidden relics, 
  mysterious lore about the depths of Undermountain, and 
  great adventure come day break.
  Adventure Overview
  This adventure can take place in Undermountain or any 
  adventure that includes mountainous, underground, or 
  hilly terrain and a city full of rumors.
  A small earthquake hits Undermountain.It doesn’t cause 
  much damage, but there are a couple of  landslides. One 
  of the landslides reveals an entrance to Undermountain 
  that was previously unknown. This entrance can be 
  deep within Undermountain or right outside it on Mount 
  Waterdeep.
  Party members will come across young NPCs who have 
  a failed flying machine that wrecks while on search of a 
  fabled book of alchemy in this cavern.
  Instead of a fabled book, the heroes instead find a portal, 
  which looks like a normal doorway, that leads to a vast 
  hidden lab and an eccentric thinker, artist, and inventor 
  who is excited about his projects and capturing the wildlife 
  of the island  in pen and paint. He is happy to share his 
  new discoveries and to help the adventurers to their next 
  conquest with the help of his invention. The heroes also 
  discover they are no longer in Undermountain once they 
  pass the portal into Leo's lab: They have entered a small 
  cave system on a floating island far above Waterdeep 
  after entering the portal.
  Adventure Hooks
  Fabled Book of Mystic Alchemy
  Young adventurers approach the party asking for aid 
  finding a fabled secret book of alchemy deep in the 
  mountains. A young girl named Helena wants to find the 
  book to impress her grandmother and to read its secrets.
  Missing from the Waterdeep
  A merchant’s son has gone missing in Waterdeep. The 
  merchant Lana says her son went out help his young 
  inventor friend, a young girl who has built a simple hang 
  glider. The last her son told her was that the two were 
  headed to the mountain to test one of her inventions.
  Strange Lights
  There are rumors in the Waterdeep taverns that 
  mysterious lights have been appearing in some of the 
  abandoned caverns of Undermountain. Some say it is 
  ghosts of the old wizards or dwarves of Undermountain. 
  Others say a mad wizard is camping out there.
  A Cry for Help
  While adventurers are questing in Undermountain, they 
  suddenly hear a cry for help coming from a nearby cavern 
  entrance.
  Dramatis Personae
  Helena is a young human woman. Her parents are 
  both carpenters, which motivated her to build her own 
  creations. She wants to impress her grandmother by 
  finding a fabled book of alchemy rumored to hold great 
  alchemical secrets of Faerûn from the goddess Mystra. 
  Helena’s best friend is a merchant’s son named Andre. 
  They have been friends since they were small children. 
  They built the hang glider together, using materials left 
  over from her parents’ inventive projects and materials 
  they found in the woods. Helena is always full of new 
  ideas and always coming across old treasure maps and 
  legends of old relics, secret societies, and forgotten 
  knowledge.
  Lana is Andre’s mother. She is a half-elf that sells elven 
  and dwarven-made armor and weapons. She is a retired 
  adventurer who runs a tent in one of the crowded 
  markets of Waterdeep and sometimes has rare magic 
  items among her wares. She was once a great fighter of 
  Waterdeep and still carries her trusty swords.
  
  12
  Leo is an eccentric artist who seems to have wandered 
  into Waterdeep through a portal. Many people thought his 
  ideas of flying machines and other inventions completely 
  mad, so he sought refuge in Undermountain, where he 
  could work on his projects in peace. He is very kind and 
  immensely curious about Faerûn, magic, and the Weave. 
  The whole planet—and the concept of magic—seems 
  foreign to him. He had never seen dragons until he moved 
  his laboratory and workshop to Undermountain. He 
  carries small daggers and a crossbow, and he knows some 
  wizard spells and cantrips. He is very humanitarian and 
  enjoys helping others with his inventions. Occasionally 
  he hunts deer and rabbit in the woods of Undermountain 
  with his crossbow. Sometimes Leo invites a few of his 
  artisan friends from Waterdeep to hang out with him in 
  his laboratory to share ideas.
  Caverns of Maestro's Hideout
  1. Cave Entrance
  The young woman is Helena, and the young man is 
  Andre. Treat Helena as a scout (MM p349) and Andre as 
  a tribal warrior (MM p350).
  Helena sees the party and shouts that her companion is 
  hurt. She asks them for help. 
  The young woman has a heavy rope which the heroes 
  can use to cross the gorge. However, she is not strong 
  enough to throw it 100 feet across the chasm.
  The gorge is 100 feet wide and 60 feet deep. A rushing 
  cave river meanders through it. There are plenty of 
  stalagmites on either side to which the rope can be 
  anchored. 
  Encourage the players to come up with a plan to get 
  the rope across. This could be anything from one of the 
  characters simply flying across the chasm and carrying 
  one end back to firing a smaller rope tied to a crossbow 
  bolt across the gorge and using the lighter rope as a pilot 
  line.
  Once the large rope is secured, creatures crossing it 
  must make a DC 15 Strength (Athletics) or Dexterity 
  (Acrobatics) check to cross the gorge by the rope 
  suspended. A failed check results in a fall into the gorge. 
  A falling creature takes 18 (6d6) bludgeoning damage, 
  lands in the water, and washes up on the sand bar in Area 
  5. 
  2. Cavern of Deep Sashelas
  The travelers tell the party that there is a fabled mystic 
  and ancient book of alchemy within these caves and they 
  came to find it. Helena asks the adventurers if they will 
  look for it while she attends her wounded friend.
  Altar of Deep Sashelas. Another deep crevice lies 
  General Features
  Terrain. The caverns lead into the depths of Undermountain. 
  The walls are deep green and blue granite. The ceilings of the 
  entrance are vaulted and seem to reach toward the heavens. 
  There is a deep crevice in the entrance chamber, likely caused 
  by the earthquake.
  Light. The caverns are dark except for those describing 
  torches or other forms of lighting.
  Ceiling Height The ceilings are vaulted and the entrance 
  with the river and gorge are intimidatingly high. Some of the 
  smaller storage rooms seem to be carved out of the granite 
  and have ceilings that are 15 feet high.
  The path up Mount Waterdeep is overgrown and full of 
  dangers such as hungry bears and rock slides. After a long 
  hike, you make it to a cave. The sun burns hot as you wipe 
  your brow with relief at finding a place to rest. 
  The sun is hot and the air wavers off the dark granite and 
  rubble as you walk into the large, dark cave opening. The 
  temperature drops and eyes adjust as you step into the depths 
  of Undermountain. 
  As you adjust to the cool darkness of the cave, you walk into 
  great commotion. Ahead, a hang glider wavers in the air with 
  two passengers. It crosses a deep gorge with a rope trailing 
  behind it. The glider begins to lean to one side and a loud 
  crack fills the air as it clips the edge of the gorge and crashes 
  onto the other side. You hear a young man’s cry of pain. A 
  young woman frantically pulls animal skins and branches off 
  the shattered glider to reach her companion.
  After you cross the bridge, you see the glider has crashed 
  into a heap of animal skins and splintered wood next to a 
  beautiful altar carved from layered blue granite. The altar 
  emits a great sense of peace before you. When you near 
  the altar, you almost sense the breeze of the water plane. A 
  beautiful male statue of a water deity stands bearing a tritan. 
  Before him is a bowl surrounded by shells, dolphins, and 
  animals of the deep.
  
  13
  
  14
  to the north of the altar. On both sides of the gorge are 
  pillars that look like a foot of a stone bridge, but there is 
  no bridge linking the two sides. 
  The statue holds an empty basin decorated with shells, 
  starfish, dolphins, and nautiluses. A successful DC 12 
  Intelligence (Religion) check reveals that the statue 
  depicts Deep Sashelas. Succeeding by 5 or more reveals 
  that Deep Sashelas is an elven deity known for sculpting 
  the oceans, corals, and islands. 
  On the altar are four jars. Each contains one of the 
  following alchemical items: oil, water, salt, and aluminum 
  shavings. The jars can be picked up.
  If a creature adds water and salt to the basin, the water 
  will glow a magical blue, and large stones begin to fly 
  from the walls to form a bridge across the gorge between 
  the pillars. The noise of them clattering together echoes 
  throughout the caverns. 
  There is enough water to fill five water skins with the 
  glowing blue water. A creature proficient with alchemist’s 
  tools can make a DC 13 Intelligence check to identify 
  the glowing liquid as a potion of water breathing that, in 
  addition to the normal abilities, gives a +1 bonus to the 
  drinker’s AC. 
  The characters will undoubtedly wish to mix other 
  substances in the basin. If they mix the substances in any 
  other way other than water and salt, one of the following 
  monsters sets will appear. Roll 1d6 and consult the table:
  Roll 
  Creatures
  1-2  
  2 blue dragon wyrmlings (MM p91) and 1 black 
   
  dragon wyrmling (MM p88)
  3-4  
  4 dire wolves (MM p321) and 4 death dogs (MM 
   
  p321)
  5-6  
  3 basilisks (MM p24)
  The jars magically refill their contents after being 
  poured into the basin. The magic glowing water remains 
  in the basin. Incorrect mixtures magically drain from the 
  basin as soon as the trap is triggered. The party can only 
  make the magical mixture once. If they fill the basin with 
  salt and water a second time, it will be plain salt water. 
  Moving a jar more than 10 feet from the altar causes that 
  jar to become non-magical forever.
  3. Vaulted Cavern
  Creature 
  One of the stalagmites is a roper (MM p261) that gently 
  shifts as its attention moves toward the adventurers’ 
  footsteps on the wet cave floor. A hero with a passive 
  Perception of 16 or higher notices this movement. 
  Giant granite stalactites loom above stalagmites, dripping 
  water into small pools and puddles. Transparent creatures 
  dart about in the pools of water. Some pools have creatures 
  glowing with bioluminescence, offering dim light around the 
  pools. 
  
  15
  If no party member notices the roper, it gets a surprise 
  round, and attacks with its tendrils as soon as a creature 
  comes within range.
  The tunnel from Area 3, past Area 4, to Area 5 slopes 
  steeply downward.
  4. The Roman Bath
  This beautiful room is a very large bath lit with torches 
  mounted in large decorative metal brackets on the walls. 
  The walls and floors around the large bath are tiled in 
  shades of blue and teal with mosaics of sea life. There are 
  two empty decorative metal wine cups on the side of the 
  bath. The bath is about three feet deep around its edges. 
  In the center a pit plunges 60 feet. Only creatures with 
  darkvision will see the chest at the bottom of the pit. 
  The chest is unlocked and held shut with a simple latch. 
  It contains a 50 gp diamond with a symbol etched into 
  it. A successful DC 12 Intelligence (Religion) check 
  reveals the symbol represents Deep Sashelas. There are 
  also large granite stones in the chest. 
  When a hero opens the chest, read or paraphrase:
  The tunnel from Area 3, past Area 4, to Area 5 slopes 
  steeply downward.
   
  5. Underground River
  This area is mostly empty. There is a small pool full 
  of cave creatures such as clear crayfish and small blue 
  glowing creatures. 
  Any creature which fell off the rope bridge will wash up 
  on the sandbar here.
  There is a locked wooden door in the granite wall 
  to the north. Metal torches are mounted to the wall on 
  both sides. A successful DC 12 Dexterity (thieves tools) 
  check unlocks the door.
  When the door opens there is an almost invisible watery 
  film over the doorway. This door is a portal that leads to 
  the rest of the dungeon, which is part of the sandstone 
  mountain within the floating island. 
  Note: After this adventure, if the floating island 
  disappears and goes somewhere else, the north wall will 
  look like a plane granite and will be a dead end.
  6. Artist’s Laboratory
  This room has several thick wooden tables covered 
  in candles, art tools, and lab supplies. Schematics of 
  marvelous inventions, animal anatomy, nature, and 
  strange artifacts cover the walls. One table is full of books 
  on topics such as arcana, alchemy, geology, and art. None 
  of them seem to be the book the travelers were looking 
  for. One table has alchemical components, beakers, a 
  lantern, and burners with jars bubbling. Another table has 
  an easel, paints, a large jar of multi-colored fireflies, art 
  supplies, and more art books. The painting is of a strange 
  flying machine. There is an unlocked door to the north. 
  Glowing creatures dart about a pool of water nearby. 
  Torches light an entrance to the north. The flames warmly 
  crackle and pop, almost welcoming you to the wooden door. 
  The latch easily slides open as a rush of bubbles dances 
  around you and rises above. Warm and cool water surrounds 
  you as look into the chest. An engulfing feeling of deep sea 
  magic fills your being as you pick up the beautifully carved 
  diamond.
  A short passage leads you to a room full of cluttered tables. 
  Beautifully crafted drawings and paintings of Undermountain 
  wildlife and dragons cover the wall. Schematics of strange 
  and wondrous inventions are scattered across the walls. The 
  candles flicker around fresh paints and a vast collection of 
  books.
  The wooden door opens to a very large, torch-lit bath. The 
  light flickers off the glistening tiled mosaic of creatures from 
  the Elemental Plane of Water. Merfolk and fish cascade the 
  walls as dolphins dive across the intricate tile designs. The 
  reflection of the water wavers across the walls as the smell 
  of wine wafts from empty wine cups on the side of the pool.
  
  16
  Jar of Fireflies. The jar of fireflies sheds bright light in 
  a 10-foot radius and dim light for an additional 10 feet. 
  The jar lasts for 24 hours.
  7. Trap Doors
  The doors are sealed shut, and are made of a dense, 
  hard stone. They cannot be opened with thieves tools, 
  or indeed opened by any physical means the characters 
  possess. A knock spell or similar magic opens a door.
  Trapped Doors. 15 feet above each door—or 25 feet 
  from the floor—is a mechanism with a star symbol. Each 
  star mechanism has AC 15. Any ranged weapon or spell 
  attack which hits a symbol will trigger the door below it 
  to open. A miss causes a bolt of magical energy to shoot 
  from the star toward the creature who made the attack. 
  The bolt causes 2 (1d4) damage. Roll on the following 
  table to determine the damage type:  
  Roll 1d6 
  Damage type
         1   
  Fire
         2   
  Frost
         3   
  Psychic
         4   
  Poison
         5   
  Lightning
         6   
  Radiant
  8. Storage Room
  This room is full of crates of various sizes that are 
  nailed shut. These crates are full of wood, canvas, wooden 
  nails, and candles. Small harmless horned beetles crawl 
  about if any of the boxes are disturbed. 
  9. Pantry Storage
  This room is stocked with crates of produce, dried 
  meats, and jars of preserved vegetables and jams that are 
  now splattered across the room. The dragons have ripped 
  open sacks of grain and haphazardly smashed into crates 
  of apples and dried fish. The door to the north leading 
  outside is wide open. It appears the dragons figured out 
  how to open the latch and break in to get to the food.
  Creatures. 4 faerie dragons, one each of the following 
  colors: green, blue, indigo, and violet (MM p133), which 
  have gotten into the crates and baskets of food. 
  10. Open Door to a Cliff
  This area is a large cliff on the side of a floating island 
  with a drop of hundreds of feet to sharp rocks below. This 
  area is a dead end. A beautiful view unfolds before the 
  adventurers as the sunset glows in oranges and pinks. In 
  the distance dragons dip and glide through the glowing 
  skies, and the heroes can see Waterdeep through the 
  clouds below.  
  A door leading outside is wide open, allowing light from the 
  glowing sunset to pour in. Two colorful faerie dragons rest on 
  large bags of potatoes and grains. Two other faerie dragons 
  play tug of war with a large piece of dried meat clenched 
  between their powerful jaws. One of them shakes its head 
  like a playful dog as it pulls hard on the salted meat.
  Outside, you stand on a cliff on a floating island soaring high 
  above Waterdeep. The sky is streaked with pink, orange, and 
  purple as the sun starts to set peacefully. You can hear the 
  rustling of trees further up the mountain as a mother dragon 
  teaches her baby dragon to fly. 
  This room is dark and has stone doors that lead to the 
  west, north, and east. 
  
  17
  11. The Runway
  Lumber and crates of building materials are stacked 
  along the walls. There appears to be a well used runway 
  with lines painted onto the sandy ground. 
  12. The Flying Machine
  This room contains a large flying machine crafted from 
  wood and canvas. It is much larger and more complex 
  than the small glider the party saw earlier.
  Leo is a painter, inventor, scientist, and thinker. He says 
  he is not quite sure if he is from this plane of existence 
  as he shows his intricate work to the party. He says he 
  is interested in learning about magic because the Weave 
  does not exist where he comes from. He offers the party a 
  ride on his latest contraption. If the party asks about the 
  mystic alchemy book, Leo knows nothing about the book 
  but says the party is free to look at the collection in his 
  laboratory. Treat Leo as a mage (MM p347).
  13. Flight!
  This is a large cliff face with a beautiful view of the 
  clouds and the lights of Waterdeep below. The large doors 
  leading out will easily allow the flying machine through 
  after going down the runway. 
  Conclusion
   
  Party members may wish to return to save the young 
  NPCs that have crashed and return them to Waterdeep. 
  The flying machine can hold everyone. Leo is willing to 
  take the party to other adventures or places of interest 
  along Undermountain and Waterdeep. Leo may also find 
  interest in Waterdeep to put his skills in art, science, 
  building, and engineering to use in trade for supplies. If 
  Leo is not summoned for help, he remains happily in his 
  lab, only leaving occasionally to order supplies for his 
  creations, hunting wild game, or spending time with his 
  artisan friends.
  This large room looms high with a cavernous ceiling. Crates 
  covered in building tools line the walls along the sandy stone 
  floor. Carefully painted white lines lead out to giant double 
  doors both to the north and the south. 
  Through the large doors stands a magnificent machine. A 
  finely-crafted wooden frame pulls taut layers of canvas along 
  their seams.  A young man with brown hair pulled back into 
  a ponytail appears out of the canvas. He puts down his tools, 
  smiles, greets you warmly, and introduces himself as Leo.
  Leo activates a mechanism which pushes open the giant 
  doors, and a cool evening breeze rushes through the warm 
  air of the cave. The large torches waver in the wind as the 
  wheels of the flying machine creak faster and faster down 
  the runaway. 
  You hold on tight, your blood burning with adrenaline and 
  excitement. A gust of wind from the mountains pushes against 
  the canvas of the machine and you see the burning lights of 
  the city below like stars in the sky. As the machine takes flight, 
  Leo yells out loud with excitement with the success of his 
  flying machine. The night sky streaked with stars opens up as 
  everyone enjoys a ride out of Undermountain.
  
  18
  Sanctuary of the Goddess
  The adventure location is designed for 4-6 characters of 
  level 6 (Tier 2, APL 6).
  Adventure Background
  During ancient times, the Drow were 
  a thriving society in the splendor of 
  Undermountain. They dwelled in intricate 
  cities in endless labyrinths of caverns. 
  Great creatures helped them pull wagons 
  of treasures and goods deep underground 
  for trade and to fill the underground 
  markets. Many prominent families lived 
  there and held great influence over Drow 
  society. One of the wealthiest families took 
  power. Not only were they keen merchants, 
  but also full of new ideas to help the Drow city 
  thrive and maybe even rejoin other nations in trade 
  who lived above ground in Waterdeep. 
  But one of their ideas created a great uprising. This 
  family worshiped a good-aligned drow deity instead of 
  Lolth. Lolth herself heard of this and turned the great 
  underground city against this family. Legend has it that 
  assassins played a hand in their demise. Others say 
  a mob came and pillaged the great house, but no one 
  truly knows who dealt the most severe vengeance on the 
  family who worshiped Eilistraee and tried to bring a good 
  alliance within the Drow society of Undermountain.
  Adventure Overview
  That ancient Drow society is long gone. Only the 
  remains of their great cities are left, crumbling deep in 
  Undermountain, the ruins just a whisper of what was 
  once a prosperous realm. One great house looms high in 
  the caverns. Its tapestries long disintegrated and floors 
  now crumbling, this symbol of Drow prosperity and 
  power still holds the last few clues of what happened 
  to the great Drow family. Their names have been long 
  lost in time after looters chiseled out their effigies, but 
  their legacy is still a secret legend in the shadows of 
  Waterdeep.
  Adventure Hooks
  Whispers in the Darkness. There are rumors in 
  Waterdeep that there are whispers and voices heard from 
  Drow ruins deep in Undermountain. Some even claim 
  they have heard children laughing deep in the shadows 
  of the old great Drow house.
  Goblin Creeping. An archeologist in 
  Waterdeep claims they saw a strange 
  goblin disappearing into some ruins within 
  Undermountain. They saw the goblin 
  wearing costly robes and carrying a great 
  staff instead of wearing tattered rags like 
  most goblin folk.
  Mysterious Ruins. While adventuring 
  through Undermountain, the adventurers 
  stumble upon towering Drow ruins. The 
  decorative carvings include statues and 
  scenes that don't seem to match most 
  Drow ruins. One can almost see amiable 
  Drow in the beautifully carved scenes. 
  Grand steps lead to a stone door left cracked 
  open.
  The Sanctuary
  As the characters approach the Sanctuary entrance, 
  read or summarize:
  General Features
  Sights, Sounds & Smells. Deep shadows caused by the 
  party's torches fill detailed, ancient Drow carvings as the light 
  flickers across it.
  It is silent exceept for the echoes of distant water dripping 
  and the sound of the adventurers' feet.
  Doors & Walls Unless noted otherwise, all doors are 
  unlocked asd made from stone (AC 20, 50 hit points).
  Unless noted otherwise, all walls a re made from smoothed 
  stone (AC 20, 50 hit points per 5 foor cube) and the ceiling 
  heights are 10 feet.
  Light. Unless otherwise noted the dungeon is unlit.
  You’ve been walking for hours, accompanied by nothing but 
  the sound of your feet echoing through the vast deep labyrinth 
  of chambers which comprises the splendor of Undermountain. 
  Your path gives into a massive cavern in which you see a great 
  castle into looming the cave wall, seemingly carved from the 
  rock. A heavy, carved stone door lies open before you.
  
  19
  
  20
  1. Entrance Hall
  When the characters open the door, read or summarize:
  This whole room is difficult terrain. Creatures who 
  wish to cross the crumbling floor and rubble must make 
  a successful DC 12 Dexterity (Acrobatics) check. 
  Creatures who fail the check fall into a room 10 feet 
  below onto a pile of rubble, taking 4 (1d6) bludgeoning 
  damage from the fall. There is no entrance or exit from 
  the lower room other than somehow climbing out of it.
  A successful DC 12 Intelligence (Religion) check 
  reveals the carvings are of the Drow goddess Eilistraee. 
  Succeeding by 5 or more reveals that Eilistraee is a good-
  aligned Drow goddess.
  2. The Throne Room
  If the adventurers walk near the walls with a light 
  source, they see ancient paintings of a Drow royal family 
  that spans over centuries. The room has been long since 
  looted and anything not made of stone has faded into 
  dust. If the heroes search the rubble in the corners of the 
  room, they find a small, ornate metal toy ball that was 
  once painted with bright colors.
  A successful DC 20 Wisdom (Perception) check 
  reveals a secret door in the northwest wall. A successful 
  DC 14 Intelligence (Investigation) check reveals that a 
  knob on the western throne can be rotated, which opens 
  the door.
  3. Hallway
  The door can be forced open with a successful DC 17 
  Strength check. 
  4. The Library
  A successful DC 18 Wisdom (Perception) check 
  reveals faint impressions of where the bodies of two 
  adults and two children lay during the fire. 
  Old graffiti messages have been hastily scrawled across 
  the walls. They are written in ancient elven, and say 
  things such as ‘blasphemers’ and ‘traitors to the gods.’ 
  Anything else in this room has collapsed to dust. 
  The south wall has markings of a recent magical 
  blast that has struck the wall; no check is required to 
  detect these markings. A successful DC 12 Intelligence 
  (Arcana) check reveals traces of a fire spell, perhaps fire 
  bolt or burning hands.
  Development. Stepping within 10 feet of the markings, 
  which characters wishing to gain more information about 
  them must do, causes a wraith (MM p302) and 4 will o’ 
  wisps (MM p301) to appear. The undead attack at once 
  and fight until slain.
  This room appears to be a vast throne room. The beautiful 
  mosaic tile has cracked and shifted with time. There is a door 
  in the north end, to the left of two large granite thrones, and 
  a door in the southwest corner in the western wall.
  This small hallway reveals a door to the south and a 
  passageway to the west. The door has been boarded up. The 
  rest of the hall is blocked by collapsed rubble. 
  The room appears to be an old study or library that was 
  been burnt out long ago. The walls are covered with ancient 
  graffiti scrawled over the signs of fire.
  Ahead is a large, vaulted room. Parts of the floor have fallen 
  in, and giant, ornately-carved fireplaces are to the east and 
  west.  A large archway looms to the north.
  
  21
  5. Old Kobold Hideout
  Inside the chest, adventures find a few rounded stones 
  along with old leaves, sticks, and wood chips. The area 
  looks as though it has not been inhabited in decades.
  6. Cave of the Living Fungus
  In this area are 2 quaggoth spore servants (MM p230), 
  2 myconid adults (MM p232), and 3 myconid sprouts 
  (MM p230). The monsters immediately attack and fight 
  to the death.
  A successful DC 15 Intelligence (Religion) check 
  reveals the statues are of Eilistraee. A successful DC 
  12 Intelligence (Investigation) check shows that these 
  statues are part of a large mechanism. The statues cannot 
  be lifted, but if both are turned a  quarter of a turn in any 
  direction, they will open the stone door, which leads to 
  Area 2.
  7. Passage
  At the north end of the passage there is an archway to 
  the right with stairs leading down to Area 8. To the left 
  is a door leading to Area 10. This door is newer than the 
  surrounding work, though still old, and is made of heavy 
  wood. It has two locks, each of which can be picked with 
  a successful Dexterity (thieves tools) check. One is DC 
  13 and the other is DC 17. The door is AC 15 and has 20 
  hit points.
  8. Chapel
  Any creature can see that the goddess looks kind and 
  good hearted. A successful DC 12 Intelligence (Religion) 
  check shows that the carvings are of Eilistraee and 
  reveals that, unlike other deities in the drow pantheon, 
  she is not a thing of twisted evil. 
  The heroes also discover that the carvings of  Eilistraee 
  and her symbolism have been chiseled over previously-
  existing art which is no longer identifiable. 
  9. Crypt
  Opening any of the tombs will trigger 2 wights (MM 
  p300) and 6 shadows (MM p269) to appear, immediately 
  attack, and fight until slain.
  A successful DC 12 Intelligence (Religion) check 
  shows that the statue is of Eilistraee.
  If the tombs are open, some will reveal charred bones 
  This is a large cavern full of stalactites and stalagmites. 
  It appears an entrance to the west has caved in and is 
  impassible. There is a stone door to the east that is shut. Two 
  stone statues of a beautiful drow goddess gracefully holding a 
  sword appear on pedestals on either side of the door. 
  You see a long hallway that was once grand. Dust lines the 
  ancient tile and cracks spider across the walls. 
  The stairs going down from the tiled passage lead to small 
  room with smooth stone benches on either side. It appears 
  candles and statues once stood here and there for offerings. 
  Beautiful stone etchings of a drow goddess appear on the 
  walls before the benches. There is also a door in the south 
  wall.
  This room is a small crypt with 10 ornately carved tombs. 
  A large, dusty statue of the beautiful elven goddess elsewhere 
  depicted stands tall before the south wall. 
  This is a small cavern that looks like it was once occupied 
  by kobolds or similar creatures after the Drow palace was 
  abandoned. There is an old fire pit, some broken crates, and 
  a shabby chest. There is a small door to the east and an 
  archway at the end of the hall that is half blocked by fallen 
  rubble, but still passable. The archway leads to a crudely-
  delved tunnel, perhaps a secret tunnel leading out of the 
  castle during the ancient times. 
  
  22
  of two adults and two children. The rest of the remains do 
  not appear singed by ancient flames. Inside one tomb is a 
  drow-style silver ring and a silver pendant, each worth 50 
  gp each. There is also a silver mirror worth 25 gp, a 10 
  gp topaz, a 40 gp emerald, and a 50 gp diamond scattered 
  in the tombs. The two small children’s tombs contain 
  trinkets—a small carved stone pony and a stone frog.
  10. Servants’ Kitchen
  The items on the tables are too damaged to be very 
  valuable. The entire collection, which is too heavy and 
  bulky for one creature to carry, might be worth 100 gp to a 
  sage or collector in Waterdeep. The stairs lead to Area 11.
  11. Tower Base
  The knightly figures are a fire elemental (MM p125) 
  and a water elemental (MM p125). They provide dim 
  light in this room. 
  If the adventurers were quiet on the lower level, the 
  elementals appear to be an a deep meditative state. If 
  combat spilled to Area 10, they are alert. If the elementals 
  are not alert, the heroes can attempt a group Dexterity 
  (Stealth) check, opposed by the elementals’ passive 
  Perception (10), to sneak past them. Failure indicates 
  the first character to reach the door opened the unlocked 
  door, which made a loud squeak. 
  If the elementals awaken, they ask the adventurers why 
  they are in their master’s tower (note the elementals only 
  speak Ignan and Aquan, respectively). The elementals 
  are peaceful as long as they aren’t attacked and the 
  adventurers don’t try to force their way past them.
  The door guarded by the elementals leads to spiraling 
  stairs going up. At the top of the stairs is an unlocked door.
  12. Upper Tower
  The goblin, named Lazuli, will not attack unless in self-
  defense. If the “heroes” attack him, treat him as a mage 
  (MM p347) armed with a staff of frost. 
  If the party convinces him they come in peace and need 
  his help, he has a few supplies for them, which include 
  2 potions of healing, a potion of invisibility, and a spell 
  scroll of chromatic orb. 
  It appears this room is the base of a tower. A water and a 
  fire elemental that look like knightly elven guards stand on 
  both sides of a wooden door across the room. The flickering 
  fire and sparks of lightning emanating from the beings gently 
  glow on the surrounding walls. 
  The door creaks open and the room is warm. A crackling 
  fire burns in a simple fireplace. Two chairs facing the fire. 
  The room is welcoming and full of simple furniture such as 
  a bed and a dining table on which is a wooden bowl of fruit. 
  You notice an elbow on one of the chairs and a pointy ear as 
  someone rests quietly in the chair. 
  That someone rises, a goblin dressed in wizard’s robes, 
  who says in a cultured, urbane voice, “Who are you, and what 
  are you doing in my home?”
  Opening the door, you see a small, round room with 
  tables, which was once an old servants’ kitchen. There is 
  a large hearth and several tables. The thick wooden tables 
  are cluttered with strange statues and artifacts of various 
  deities that seem to be a collection of ancient art found in 
  Undermountain. Most are too heavy to lift and are drow or 
  dwarven in appearance. The room appears to have been 
  recently cleaned. There is a small doorway in the far wall 
  with stairs leading up.
  
  23
  Whether or not he helps the heroes, complaining that 
  he is very busy, at the earliest opportunity he guides the 
  heroes out a door and down a long spiraling flight of 
  stairs that leads to Area 13. 
  If the characters ask about the fire 
  or the charred bones, Lazuli tells 
  them he found the ancient bones 
  in the library and laid them to rest 
  in the crypt. 
  At your option, you can use 
  Lazuli as a recurring NPC in 
  Undermountain.
  13. Portals
  The portals go wherever 
  you want, within or outside 
  of 
  Undermountain. 
  At 
  your option, the portals 
  can permanently close once 
  the adventurers have passed 
  through, or they can remain 
  open so the players can return to 
  Lazuli’s dwelling.
  This round room contains 
  three portals, each swirling and 
  sparkling with magical energy. 
  There are no other exits.
  
  24
  UWPS - Undermountain 
  Water Purification & 
  Sanitation
  “You take a pee in here, what do you think happens? You 
  think it just sits there? Can you imagine what it would smell 
  like in this dungeon if everyone’s pee just sat there? What 
  the fountains would look like if nobody was cleaning up the 
  water?”   - Hisbis Brizznickel
  The 
  adventure 
  location 
  is 
  designed 
  primarily 
  for 
  exploration and roleplaying and 
  can be used with any party of 
  6th level or higher.
  Adventure 
  Background
  Who keeps the dungeon clean? 
  When 
  adventurers 
  relieve 
  themselves, 
  where 
  does 
  it 
  go? Where does water for 
  fountains down here come 
  from? The answer is UWPS: 
  the 
  Undermountain 
  Water 
  Purification 
  and 
  Sanitation 
  area. 
  Wastewater 
  magically 
  arrives 
  in 
  this 
  sanitation 
  department, where it filters 
  through an enchanted swamp 
  and down into a sanitation 
  facility before being transported back to areas all around 
  Undermountain. The entire facility is staffed by modrons 
  and run by an eccentric gnome named Hisbis Brizznickel.
  Recently the modrons have been impeded by some new 
  arrivals in the enchanted swamp; a tribe of lizardfolk 
  have planted themselves in the area under belief it is 
  their promised land, and they aren’t interested in leaving.
  Adventure Overview
  The characters discover the entrance to the UWPS, 
  which leads them into the foul-smelling swamp of 
  sanitation. Here they might encounter lizardfolk who 
  warn them away from their tribal territory.
  In exploring the swamp, the characters find their way to 
  the sluice gates and access to the lower level of UWPS, 
  where they meet overseer Hisbis Brizznickel, who seeks 
  a solution to the aggressive lizardfolk living in the swamp.
  The characters can solve Hisbis’s issue in a number of 
  ways, including negotiating peace with the lizardfolk 
  tribe. They might discover that the lizardfolk tribe 
  actually improves the swamp’s efficiency, making them 
  an odd but welcome addition to the sanitation process.
  Adventure Hooks
  The Customer Appreciation 
  Letter
  Before the characters enter 
  Undermountain, a mysterious 
  figure gives them a letter 
  addressed to 'UWPS,' telling 
  them they'll know it when they 
  see it. The letter has a wax seal 
  of a strange ring-shaped city. 
  Opening the letter reveals it is 
  a customer appreciation letter 
  from 
  'Marvins 
  Magnificent 
  Modrons.'
  Lizardsign
  Rough letters in draconic, 
  scratched 
  into 
  the 
  walls 
  of 
  Undermountain 
  with 
  a 
  humanoid-sized 
  creature's 
  claws, 
  point 
  the 
  way 
  to 
  'Semuanya's chosen land.' Following the markings 
  through Undermountain's corridors leads to a strange 
  door with a metal placard beside it.
  The UWPS
  1. Entrance
  A huge iron door ten feet wide and twelve feet high is 
  secured to the wall by heavy metal hinges. The door is ajar, 
  and a heavy, humid bog smell is emanating from the foot of 
  space between the door and jamb.
  
  25
   Placard. A bronze placard is bolted to the wall beside 
  the door. Its lettering is enchanted, and when first looked 
  at is impossible to make out. After a moment, the letters 
  writhe, shimmer, and settle, and a creature will either 
  see the words in common, elvish, draconic, or dwarvish, 
  depending on its native tongue. The placard reads: 
   
  U.W.P.S. 
  UNDERMOUNTAIN WATER PURIFICATION AND SANITATION 
  IF IT DRIPS, FLOWS, SLOSHES, OR SPATTERS – WE CLEAN 
  IT 
  NO GENERAL SOLICITORS 
   
  The door is heavy, but opens easily on its well-maintained 
  and oiled hinges. Beyond the door is the Swamp of 
  Sanitation (Area 2). 
  2. The Swamp of Sanitation 
  The largest area of the UWPS is the Swamp of 
  Sanitation, a massive wetland area that mixes natural 
  and arcane components. 
  
  26
  2A. Swamp Lizardfolk 
  A tribe of lizardfolk has recently found its way into the 
  UWPS and established their home in the Swamp of 
  Sanitation. Their shamans have used plant growth to 
  harvest enough grasses and other materials to build their 
  huts, which are located near the northwest corner of the 
  Swamp. 
   
  Modron clashes. The lizardfolk are fiercely territorial 
  and have attacked the sluice gates (see Area 2B) several 
  times. The modron bodies disintegrate when killed, but 
  the lizardfolk have used the modrons’ weapons and tools 
  to make warding-monuments to mark the edge of what 
  they believe is their territory. The lizardfolk are extremely 
  wary of non-modrons but will refrain from attacking 
  immediately, believing strange newcomers could be an 
  omen from their deity, Semuanya, to ensure their survival. 
   
  Theocratic rule. There are approximately three dozen 
  lizardfolk living in the tribe, led by a trio of lizardfolk 
  shamans; Thess, Kss’ik, and Hiyuu. The tribe wandered 
  Undermountain for years, and believes this swamp is a 
  holy gift from Semuanya. 
  2B. Eastern Edge 
   
  Sluice Gates. Two huge sluice gates are located along 
  the east edge of the swamp. From here, the water filters 
  through and falls down into the Maintenance Area (Area 
  3). The gates have filters which remove most of the 
  remaining major impurities from the water. When the 
  filters need to be cleaned, the sluice gates can be raised, 
  cutting off waterflow to the Maintenance Area. 
   
  The two sluice gates are some distance apart, and each 
  is manned by a team of modrons. Each gate is supervised 
  by two quadrones (MM p226), which are tasked 
  with defending the gates against damage, monitoring 
  waterflow through the gates, ensuring the sluice gate 
  filters are maintained, and commanding monodrones to 
  accomplish the first three tasks. Each gate has a group of 
  ten monodrones (MM p224) that follow the commands 
  of the quadrones, and are most commonly tasked with 
  cleaning the gate filters as needed. 
   
  Service tunnels. On opposite ends of the eastern 
  edge of the swamp are maintenance doors, behind 
  General Features
  Arcane wetland. The plants and terrain of the swamp are 
  real and living, but a detect magic spell or similar effect reveals 
  a faint aura of abjuration magic on the plants and waterways. 
  The magic here is a simple, permanent enchantment which 
  encourages the plants to remain healthy and strike the perfect 
  balance for optimal water flow. 
  Shitstorms. 
  Moisture 
  from 
  across 
  the 
  levels 
  of 
  Undermountain magically evaporates and reappears in clouds 
  over the Swamp of Sanitation. These clouds are the first step 
  of the sanitation process, filtering out the first impurities and 
  causing the rest to fall onto the swamp in heavy downpours. 
  The filtration of the clouds is nowhere near complete, and the 
  rainfall from the storms is a torrent still containing elements 
  of the blood, urine, sweat, fecal matter, and water that has 
  been magically transported here from across Undermountain. 
  Waterflow. The placement plants and terrain is designed 
  to maximize waterflow in a uniform direction. The natural 
  function of a wetland—its filtering effects—has been 
  deliberately optimized and maximized by cunning design. As 
  the water is removed of impurities, it eventually winds up at 
  the sluice gates in Area 2B. 
  
  27
  both of which are service tunnels sloping down to the 
  Maintenance Area (Area 3). The doors are not locked. 
   
  3. Maintenance Area 
  The Maintenance Area is as artificial in appearance 
  as the swamp of sanitation is natural; it is comprised of 
  mechanical structures and metal walkways. It is set at 
  a lower elevation than the Swamp of Sanitation, as the 
  swamp’s waterflow through the sluices falls down into 
  the Sanitation Pools (3A). 
  3A. Sanitation Pool 
  Water from the sluice gates cascades down into one 
  large pool. The Sanitation Pool is sectioned off with a 
  gridlike pattern of ten-foot-wide metal walkways. Each 
  large squared-off section of the pool has mechanical rods 
  above it, which are intermittently lowered into the water 
  by nearby control panels. These panels are constantly 
  manned by monodrones tasked with lowering the 
  mechanism into the pool at regular intervals (every 5-10 
  minutes). The device is a large-scale magical contraption 
  enchanted with effects similar to the prestidigitation 
  cantrip and the purify food and drink spell. Together, the 
  spells purge large volumes of water of their remaining 
  impurities. 
   
  Modrons. As noted above, each squared-off section 
  of the sanitation pool has a monodrone stationed 
  permanently at its control panel. Six tridrones (MM 
  p225) patrol the walkways and are tasked with regulating 
  the monodrones, defending the panels from attack, and 
  maintaining the equipment as needed. Three quadrones 
  can be found in this section, instructed with the same 
  tasks as the tridrones and additionally overseeing the 
  tridrones themselves. The quadrones’ fourth task is to 
  direct unauthorized (but nonhostile) personnel to Area 
  3B. 
  3B. Dispersal Facility 
  Purified water from the Sanitation Pool is piped into the 
  Dispersal Facility, where it awaits final preparation before 
  being returned to where it is needed in Undermountain. 
  The facility is a sprawling warehouse of vats and constant 
  activity, as modrons of all kinds swarm about performing 
  their tasks, overseen by Hisbis Brizznickel. 
   
  Preparation vats. Hundreds of large vats contain water 
  that is treated with various additives. If the water is going 
  to be used for a fountain of pure drinking water, it’s sent 
  out as pure drinking water; if it’s supposed to replenish 
  a pool where the water is poisoned, the modrons add 
  the appropriate poison; if it’s supposed to have dead rats 
  floating in it, well... 
   
  It’s not entirely clear where the modrons acquire this 
  massive variety of additives. Only Brizznickel is permitted 
  to requisition the materials, and even he isn’t sure half 
  the time where this stuff comes from. 
   
  Dispersal portals. A maze of narrow pipes underneath 
  the dispersal facility diverts the final product to one of 
  hundreds of portals, which (apparently) connect to every 
  relevant fountain, pool, puddle, and body of water the 
  UWPS services. 
   
  Marut. A massive marut (MToF p214) is motionless 
  against one wall of the facility, tucked out of the way in an 
  alcove. with its massive, single eye staring unwaveringly 
  forward. The marut’s instruction, as far as Hisbis knows, 
  is to ensure the dispersal facility is protected. It has never 
  activated, and has never responded to any instruction 
  Hisbis has ever attempted to give it. 
   
  Hisbis Bizznickel. The facility’s foreman is a wildly 
  eccentric gnome named Hisbis Bizznickel (LN gnome 
  mage). Hisbis has the businesslike competence of a union 
  boss and the social grace of a gnome who spends literally 
  all of his time surrounded by modrons. Remarkably, he 
  has learned the modron language and can replicate its 
  sound of precise clicks and whirring sounds. 
   
  Hisbis primarily instructs pentadrones and quadrones 
  who help him keep track of supply orders and the need 
  for replacement modrons. Despite his stressed rants 
  about ‘budget,’ Hisbis would be the first to admit that he 
  has no idea who, if anyone, is actually paying for supplies 
  and obedient modrons; Hisbis shoves written supply 
  orders into a mail slot in his office and the requisitioned 
  materiel kind of just...shows up from somewhere. 
   
  4. UWPS and the Lizardfolk 
  
  28
  As noted above, the lizardfolk in the Swamp of 
  Sanitation have attacked the sluice gates and used 
  modron tools to make totems marking the edge of their 
  perceived territory. Hisbis sees the lizardfolk as pests 
  who threaten the work of the UWPS. He offers the 
  adventurers a piece of special gear if they can deal with 
  the problem (see Reward, below). 
   
  Odd phenomenon. Hisbis admits that despite the 
  destruction and replacement of multiple modrons at the 
  sluice gates, the efficiency of the swamp of sanitation 
  has actually improved since the lizardfolk tribe was 
  established. 
   
  Investigating adventurers who speak with the tribe 
  might be able to piece together that the lizardfolk 
  shamans’ use of plant growth for the tribe’s needs is 
  actually improving the filtering properties of the 
  swamp. Sharing this information with Hisbis 
  Bizznickel may sway him toward letting the 
  lizardfolk remain—if other rules for peace 
  can be established. 
   
  Possible Resolutions. 
  The adventurers might choose to roust the lizardfolk by 
  combat, in which case the tribe might very well fight to the 
  death to defend their territory. Alternatively, Thesk, Kss’ik, 
  and Hiyuu might agree to leave the modrons in peace 
  as long as their territory in the swamp is respected. 
  In addition, the lizardfolk are happy to repel (and 
  eat) any other threat that might wander into the 
  swamp from elsewhere in Undermountain. 
   
  Reward
  If the issue with the lizardfolk is resolved, 
  Hisbis rewards the adventurers with a pair of 
  gloves of safe handling. 
  Gloves of Safe Handling
  Wondrous item, uncommon 
  These look like a pair of thick, green rubber gloves. 
  Normally made for modrons handling contaminated 
  substances, this pair is sized for humanoids. You can 
  use a bonus action to speak the command word. 
  For 1 minute, the gloves give you resistance 
  to acid and poison damage, and advantage on 
  saving throws against the poisoned condition. 
  Once you use the gloves in this way, they can’t do so again 
  until the next dawn. 
  
  29
  Keeper of Secrets
  The adventure location is designed for 
  4-6 characters of level 7 (Tier 2, APL 7).
  Adventure Background
  Dumathoin is the dwarven god of 
  Secrets and Treasure. Abbathor is the 
  dwarven god of Greed and Avarice. These 
  gods and their followers often come into 
  conflict. This dungeon is an example of 
  this conflict.
  Long ago the Melairkyn dwarves inhabited the dungeon 
  now known as Undermountain, and it was a vast and 
  powerful empire. Over time it began to fragment into 
  enclaves. The temple of Dumathoin was—by design—
  founded in an isolated location of the dungeon, where the 
  priests felt their treasure and secrets could be better kept 
  away from prying eyes. 
  Unfortunately they eventually drew the attention of the 
  greedy followers of Abbathor, who attacked the isolated 
  temple. Powerful magics were wrought, the very earth 
  cracked, and an underground river spilled into the 
  complex. 
  The invaders, summoning water elementals, were able 
  to overcome the reclusive priests, but in their arrogance 
  could not pierce the protections on the portal to the chapel 
  and treasure room. They died to their own elementals as 
  the trapped creatures reverted to their savage nature. 
  Now avaricious dwarven spirits haunt the temple, still 
  seeking access to the treasure they were denied.       
  Adventure Overview
  The characters enter the ruined temple and discover its 
  elemental defenders. 
  The altar is locked away behind a simple yet troublesome 
  ward that requires the sacrifice of something both 
  valuable and secret. 
  Searching the library they may discover secrets both 
  useful for their further journeys and perhaps to open the 
  warded doors.
  Entering the altar room allows access to Dumathoin’s 
  altar and its divination powers, but also rouses the 
  vengeful spirits of the thwarted invaders.  
  Adventure Hooks
  Discovery by Chance….
  The adventurers may simply stumble 
  onto the Temple as part of their travels 
  within the halls of Undermountain.
  Or by Design…
  The adventurers may have heard that the 
  temple of Dumathoin exists, and has both 
  a library of lost secrets, and is rumored to 
  have the power to reveal divine secrets if one can 
  overcome its remaining protections and master the altar.  
  1. Grand Entry
  General Features
  Terrain. The entire complex is worked stone except for 
  cave-ins (Areas 2a and 5a).
  Light. There is no light anywhere except Area 6. The 
  lighting conditions are based on the party’s resources. 
  Ceiling Height. The tunnels are all 10 feet in height, and 
  chambers have their height stated under their descriptions.  
  Flooding. The lowest points in the complex – areas 
  2 and 4 – are under 2 ½ feet of water, and are difficult 
  terrain for any creature without a swim or fly speed.
  Summoning. The Temple is warded against summoning 
  magic, though the wards are damaged and fading. Every 
  time a spell is cast that summons creatures, a DC 12 
  spellcasting ability check must be made or the spell fails. 
  Items that summon creatures make be invoke with a 
  DC 12 Intelligence (arcana) check or also fail.  After the 
  spell or effect’s duration expires, the creatures remain, 
  uncontrolled by the caster and reverting to their natural 
  disposition. You have discretion as to what the creature’s 
  actions might be.  
  The smooth, unremarkable stone of the endless halls 
  of Undermountain slowly begins to change. At first it is 
  a simple runic carving at the top and bottom of the side 
  walls, but as you progress the carvings become more 
  elaborate, forming a maze-like pattern that encompasses 
  all the walls, ceiling and floor. 
  The pattern is so mesmerizing that you barely register 
  what looks like a huge chamber up ahead.
  
  30
  The pattern is hypnotic. Any character stating that 
  they examine, search or look closely at the pattern must 
  make a DC 12 Wisdom saving throw. On a failure, that 
  creature is Stunned for 1 minute. A creature is shaken 
  from this state by being roused by a comrade, or by 
  taking damage. 
   
  A DC 12 Intelligence (Investigation) check (subjecting 
  the searcher to the above effect) reveals a single word 
  repeatedly written in dwarven script (Dethek Runes) in 
  the otherwise random symbols. It reads “Xoth”, which 
  translates as “secret or special knowledge.”
  2. Main Chapel
  The chamber is 40 feet high from floor to ceiling, with 
  each of the raised areas being 10 feet from the floor. 
   
  The water is 3 feet deep, and acts as difficult terrain. It 
  is also uncomfortably cold.
   
  20 feet above the floor on the east side is a one-way 
  crystal window into the high priest’s quarters. It is 
  magically opaque from this side, appearing to be an 
  unremarkable part of the wall. It is magically hardened 
  and cannot be broken. Anyone using detect magic within 
  range can detect the auras of abjuration and illusion 
  magic.   
   
  There are three water elementals (MM p125) living in 
  the water, accidentally entering with the water from the 
  cave in, and since unable to leave. They slew the duergar 
  invaders long ago, and lie semi-dormant in the chapel. 
  They will attack anyone disturbing the water in either the 
  main chapel or the library (area 4), fighting until slain. 
  If the characters manage to avoid disturbing the water 
  in their actions (through flight, or other methods) the 
  elementals remain unaware of their presence.  
   
  Searching the floor level takes 10 minutes per 5 
  foot section. There are seven corpses of tomb robbers 
  scattered about, but time, water and the violent attentions 
  of the elementals have destroyed almost everything of 
  worth. Each 5 foot section has a 5% chance of yielding 
  something valuable amongst the junk:
  Roll 1d6     Result
       1 
      1d10 copper pieces
       2 
      1d8 silver pieces
       3 
      1d4 gold pieces
       4 
      A usable weapon (DMs discretion)
       5 
      A single piece of gear from the Adventuring 
   
      Equipment table.
       6 
      A single gem worth 1d4x10 gold pieces
  The steady drip of water can be heard as you look 
  out over the huge ruined chapel before you. The earthy 
  scent of mould hangs heavy in the cold, moist air.  
  Once-intricate stonework has been shattered, possibly 
  by an earthquake, and water has poured in from 
  a fissure in the west wall, cascading down over a 
  collapsed section of stonework. The water has covered 
  the floor, obscuring the lower section of the split level 
  room.
  What is left is a strange series of islands as the 
  upper sections still protrude from the flood below. Four 
  massive statues of a regal dwarf in robes glare down 
  from each of the corners of the room, though the 
  northwest one has partially collapsed. Of the six floor-
  to-ceiling columns that support the chamber, three have 
  shattered, leaving a collection of partially submerged 
  rubble across the floor. 
  At either end stand raised platforms, with stone stairs 
  leading down into the dark water. The entrance area 
  is plain except for two life sized statues of armoured 
  dwarves that flank you, while at the opposite end great 
  bronze portals stand closed. There seem to be several 
  corpses before them.
  Finally, at the water level, passages lead off the both 
  sides.
  Adjusting this Encounter
  Here are some suggestions for adjusting this  
  encounter, according to your group. These are not 
  cumulative.
  • 
  Very Weak: Remove 1 water elemental
  • 
  Weak: Reduce the hit points of each elemental by 
  40 
  • 
  Strong: Increase the hit points of each elemental 
  by 40 
  • 
  Very Strong: Add 1 water elemental
  
  31
  
  32
  2a. Blocked Tunnel
  The eastern tunnel is blocked by a tightly packed wall of 
  debris. Any attempt to excavate the area causes a cascade 
  that deals 8 (2d6) bludgeoning damage to anyone within 
  5 feet of the collapse, though a DC 12 Dexterity saving 
  throw can be made to avoid the damage. The rock falls 
  are effectively endless. 
  3. The Altar Doors
  The doors are enchanted and cannot be damaged or 
  opened by any means save that inscribed on the door 
  plaque. 
  The plaque is written in Dethek runes, so any creature 
  that is proficient in the dwarven language can read it. 
  It says: “Seekers offering that which is both valuable 
  and unique may discover the wisdom of the Keeper of 
  Secrets.”
  The quote literally describes how to open the door. An 
  object that is both valuable (at least 100gp) and genuinely 
  unique must be pressed to the door or presented before it 
  in offering to Dumathoin. If the players don’t immediately 
  guess the mechanism, you can let the characters 
  make a DC 12 History or Religion check to make the 
  determination.
  The characters may already possess such an object. 
  You decide if an object meets the criteria. Otherwise the 
  crown in the High Priest’s Quarters is a sufficient offering.  
  If the characters use an appropriate offering in an 
  appropriate way, the doors swing open easily and the 
  object disappears. Creatures offering up unworthy objects 
  take 1 point of psychic damage as they incur Dumathoin’s 
  displeasure. 
  The dwarf corpses have little of value on them as 
  tomb raiders have picked them clean. A successful DC 
  18 Wisdom (Medicine) check reveals that the corpses 
  are actually duergar. Only scraps of armor and clothing 
  remain. A holy symbol of Abbathor (an iron talisman 
  depicting a jewelled dagger) is hidden under one of 
  the corpses, and can be found with a DC 8 Wisdom 
  (Perception) check, and identified with a DC 14 
  Intelligence (Religion) check.  
   
  Any ability that can detect evil or undead will generate 
  an oddly inconsistent reading from the corpses. While 
  the corpses are not undead, they do remain the physical 
  tether the disturbed spirits of the duergar. Damaging, 
  destroying or moving the corpses has no effect, though 
  anyone who does so hears vaguely menacing whispers 
  until the undead actually coalesce. 
  Development. If a character manages to open the 
  doors, the restless spirits of the duergar coalesce into 
  actual undead, their hate and avarice giving them drive. 
  The spirits form 4 wraiths (MM p302) which immediately 
  attack.  
  Massive double doors of bronze dominate this raised 
  platform. Each is carved with the symbol of Dumathoin – 
  a diamond inside a mountain - below which is a depiction 
  of an anvil. A plaque above the door displays a phrase in 
  Dethek runes.
  On the otherwise clear area before the door sprawl four 
  ancient corpses garbed in rusted and rent plate armor. 
  From their size, shape, and remaining facial hair they were 
  clearly dwarves.   
  Adjusting this Encounter
  Here are some suggestions for adjusting this  
  encounter, according to your group. These are not 
  cumulative.
  • 
  Very Weak: Replace two wraiths with specters 
  (MM 279)
  • 
  Weak: Reduce the hit points of each wraith by 20 
  • 
  Strong: Increase the hit points of each wraith by 
  20 
  • 
  Very Strong: The lead creature, a former priest of 
  Abbathor, is a ghost (MM 147) with maximum hit 
  points (80) 
  
  33
  4. The Library
  All noises are strangely muted in here, though not 
  silenced (see below).
   
  The tablets are ancient books, their faces carved 
  with Dethek runes and their spines showing the titles 
  (or descriptions). Each ‘book’ weighs 5 lbs. In its day, 
  this library held rare and precious secrets, but in truth 
  much of the content has become common knowledge. 
  Nevertheless, referencing the library offers advantage on 
  any History, Religion or Arcana checks to do with dwarves 
  and dwarven society. At your discretion, characters may 
  find useful information here referring to other areas of 
  Undermountain from the time of the Melairkyn Clan, but 
  not after. If you intend to run Hunger of Abbathor from 
  this compilation, the library has a reference and a map 
  to the duergar temple, as well as a warning to “beware 
  the treasure guardian within” (but no more information 
  than that).  
   
  If any of the tablets are damaged or taken from the 
  room, the offender is cursed with 
  silence (like the spell), unable to make 
  any kind of sound until the theft or 
  damage is rectified. A remove curse can 
  end this effect. 
   
  On the second level there is an odd 
  tablet that just has the word “Xoth” 
  on the spine. If pulled, it triggers a 
  section of the bookshelves to sink into 
  the floor, revealing a small room. The 
  secret door can be found with a DC 15 
  Wisdom (Perception) or Intelligence 
  (Investigation) check. Anyone who 
  investigated the Grand Entry and discovered the writing 
  there has advantage on this check.    
  4a. Secret Room
  An arcane circle is inscribed on the floor in this 
  otherwise bare chamber. Stepping on it instantly 
  transports a creature to the High Priest’s Quarters (Area 
  5). A DC 15 Intelligence (Arcana) check identifies it as 
  an active teleportation circle, but not where it goes. A 
  detect magic shows it to be conjuration magic, and an 
  identify spell indicates its purpose and target location.
   
  The secret door is easily identifiable from this side, and 
  there is a small button on the wall next to it that opens 
  and closes it. 
   
  5. High Priest’s Quarters
  The inscribed circle is an active teleportation circle that 
  transports creatures to and from the library. See Area 4a 
  for full details.
   
  The window into the chapel is made 
  of magically-hardened crystal. Any 
  creature on this side can see through it, 
  but it is opaque from the chapel side.
   
  The tablet on the desk is a half-
  finished catalogue of the crown. A 
  delicate hammer and chisel lie nearby. 
  The tablet is in Dethek (dwarven), and 
  suggests the crown is a relic from a lost 
  dwarven outpost called Veldarheim, 
  which was reported destroyed by 
  goblins in 309 DR (more than 1100 
  years ago). The entry begins to record 
  The water-filled passage opens up into a domed chamber 
  thirty feet in height, culminating in a domed ceiling. A set of 
  stone stairs leads up to an open balcony level ten feet from 
  the floor. 
   
  Shelves line the walls on both levels, filled with rows of 
  stone tablets with Dethek runes on their spines. 
   
  Partially submerged in the centre of the lower floor is 
  a stature of a robed dwarf holding a finger to its lips as if 
  commanding silence. It is flanked by two stone tables that 
  barely protrude from the water.
  This spartan room has the remnants of stone furnishings, 
  though most have been split and sundered. A broken desk 
  lies against the north wall, a stone tablet and bent, dust 
  covered crown.
  To the south side of the room is a blocked stairway and a 
  runic circle inscribed on the floor. 
  To the west a window overlooks the chapel below. 
  
  34
  the location’s unearthing, but stops abruptly.
   
  The crown itself is silver chased iron, set with twelve 
  bloodstones. It is worth 150gp, and would serve as a 
  sufficient sacrifice to open the doors in Area 3.   
  5a. Blocked Stairs
  Much like the area at 2a, this is effectively impassable.
  6. The Altar of Dumathoin
    
  The chamber extends an infinite distance in either 
  direction, becoming an extradimensional space after the 
  first 20 feet so it doesn’t affect any of the levels above 
  or below. Attempting to reach either end results in 
  frustration and heartbreak for seekers.
   
  The niches in the walls hold an incalculable fortune in 
  wealth, but are all blocked by wall of force effects that 
  fit like invisible tiles over the inner surface. Each niche 
  could be accessed by destroying its individual wall of 
  force if a creature possessed the power to do so. The 
  stone behind each is impervious to all attempts to alter 
  or bypass. Any creature that actually manages to open 
  any of the niches may take the treasure within (ranging 
  from 100 to 1000gp value) but is subject to Dumathoin’s 
  Curse (see below).   
   
  The real treasure here is the anvil. Any creature that has 
  made an acceptable sacrifice may enter the shaft of light 
  and kneel before the altar, gaining the effect of a commune 
  spell, the duration of which commences as they enter the 
  light. Repeatedly sacrificing acceptable objects allows 
  multiple uses of the altar, but the cumulative effects of the 
  spell do apply. Any other creature attempting to enter the 
  light finds it solid like stone. The anvil cannot be moved 
  or damaged by any means.   
  Dumathoin’s Curse
  At dawn each day, one random item you own (not 
  necessarily carry) worth greater than 1gp turns to 
  worthless lead. This will never be an item that rightly 
  belongs to Dumathoin.
  This curse can be suppressed for 24 hours by remove 
  curse, but can only be permanently removed by a wish 
  or returning any stolen items to their rightful place in 
  Dumathoin’s Vault. 
  Beyond the huge bronze doors is a roughly cylindrical 
  chamber that extends vertically out of sight both above and 
  below you. The walls are lined with thousands of niches 
  containing glittering treasures of every imaginable type.
  The chamber has a stone floor extending from the door, 
  though it doesn’t reach the walls at any other point. In the 
  centre of this floor is a silvery anvil resting on an onyx 
  base, bathed in a shaft of light that extends down from an 
  unknown source above.   
  
  35
  The Mouthers of Madness
  The adventure location is designed for 4-6 characters of 
  level 8 (Tier 2, APL 8).
  Adventure Background
  Archaelogist Willem Dyer entered Undermountain 
  with a team of assistants to find chambers belonging 
  to a long-lost empire. Dyer’s expedition was successful, 
  but at a terrible cost. One of the expedition’s members, 
  Phinean Ackels, was secretly a cultish servant of the 
  Abolethic Sovereignty, the rulers of this lost empire. 
  Phinean betrayed the expedition with his fellow cultists. 
  Dyer escaped, only to die paranoid and insane in the 
  expedition tents outside.
     
  Adventure Overview
  The characters discover the abandoned tents of the 
  expedition outside the entrance to the dungeon area. 
  Inside one of the tents they 
  discover the body of Willem 
  Dyer and his journal. Entering 
  the dungeon area, the characters 
  discover a circular chamber with 
  words carved onto the floor. The 
  words and journal provide clues 
  to opening the next area.
  In the main chamber of the 
  dungeon, 
  the 
  characters 
  can 
  enter the final room by finding 
  and 
  defeating 
  the 
  traitorous 
  Phinean Ackels, who carries the 
  seal needed to open the final set 
  of doors. Inside the last chamber 
  is a well and maddening light, 
  from which appear foul aberrations. When the horrors 
  are finally defeated, one of the characters finds an item in 
  their possession; a token of the lost Abolethic Sovereignty.
  Adventure Hooks
  The Lost Expedition
  A scholar from Candlekeep approaches the characters in 
  the Yawning Portal. He's looking for a colleague, a man 
  named Willem Dyer. He believes Willem was gathering 
  a group to delve into Undermountain on a research 
  expedition and hasn't heard anything since.
  The Whispers
  While in Undermountain, one or more characters hear 
  soft whispers echoing through the corridors. Following 
  their source leads them to the double doors and 
  expedition tents outside. The whispers stop as soon as 
  the tent containing Willem's body is opened.
  1. Entrance 
  Expedition tents. The two canvas tents are each big 
  enough for three Medium-sized creatures to sleep in. 
  The canvas is worn and has numerous holes, but the 
  structure of the tents still 
  holds up. Between the two 
  tents are five bedrolls, along 
  with a set of mason’s tools 
  and 
  cartographer’s 
  tools. 
  Inside one of the bedrolls is 
  the body of Willem Dyer (see 
  below). 
   
  Willem Dyer. The body of 
  this half-elf is pale and cold, 
  though there is no obvious 
  cause of death. His clouded 
  eyes are wide open and fixed 
  on the tent’s entrance, as 
  if waiting for something to 
  enter. His journal is clutched 
  in one hand, a now-dry pen in the other. 
   
  Willem’s Journal. The journal identifies its owner as 
  an archaeologist who studied for a time at Candlekeep. 
  Many of the journal’s pages are missing, possibly torn out; 
  the first page details a group consisting of Willem, his 
  hired bodyguards, a member of Waterdeep’s mapmaker’s 
  guild named Lira Peabody, and a wizard named Phinean 
  Ackels with several unnamed assistants. They were 
  looking for “an outpost of a fallen empire” that seemed to 
  predate known history. 
   
  A set of stone double doors, 12 feet high and 8 feet wide, 
  stands closed. Whirling, hideous shapes are carved in relief 
  on the doors, creating the merest suggestion of a shape that 
  cannot be fully identified. Two tents are pitched next to the 
  stone doors. 
  
  36
  The last, shakily written page states that “the others 
  have fallen” and that Willem is “the only one to survive 
  without being changed.” He writes that he is terrified of 
  leaving the comforting confines of the tent, but fears at 
  any moment “one of those things” will come through the 
  door. His final scrawled line is “I dare not sleep. I dare 
  not sleep.” 
  2. Xxiphu Rises 
  As the characters approach, read or summarize: 
  Floor carvings. The writing on the floor is written in 
  Deep Speech. Translated, it reads “WHAT IS ABOVE IS 
  NOW BELOW, AND SHALL BE ABOVE AGAIN. THE 
  KEY OPENS AS XXIPHU RISES.” 
   
  Journal page. The player character with this highest 
  This circular chamber is 40 feet in diameter and 30 feet 
  high. Set into alcoves around the perimeter of the floor and 
  in rowed niches all the way to the ceiling are hooded stone 
  figures, empty voids of shadow where their faces would be. 
  The disturbingly lifelike detail of their robed bodies is made 
  all the more unsettling by the hint of writhing, inhuman 
  anatomy hidden under the stone-depicted cloth. Lines of 
  flowing script are carved in a spiral on the floor. 
  
  37
  Passive Perception notices the corner of a torn-out 
  journal page barely pinned under the far door. The page 
  can be easily retrieved; it’s a page from Willem’s journal, 
  which includes many excited, shorthand notes about 
  this current room. He states the script on the floor is “an 
  Espruar elvish script of unknown language.” He later 
  provides the translation (see above), stating that Phinean 
  provided the translation “but refused to acknowledge 
  where he learned this tongue.” The page identifies one 
  section of the strange script as ‘Xxiphu,’ noting that 
  Phinean pronounced it as “ZEE-foo.”
   
  Xxiphu rises. Investigating the floor finds an instance of 
  the name “Xxiphu” in Deep Speech; creatures who cannot 
  read Deep Speech can at least match the recreation of 
  the word as written in the aforementioned journal page. 
  Examining this section of floor reveals that the section 
  with “Xxiphu” on it has a square seam surrounding it: the 
  section of the floor can be gripped and pulled upward. The 
  floor section is attached to a stone, gear-toothed pillar. 
   
  When the pillar is lifted to its maximum height (about 
  two feet), the far door (to Area 3) opens. As it does so, a 
  magic mouth spell activates on the statues in the room. In 
  Deep Speech, they intone in a chorus of buzzing voices 
  “Long do we wait for the day when the Eldest shall rise, 
  when long-buried Xxiphu shall rise, and unlock the 
  heavens with the Key of Stars! Ia! Ia! Xxiphu rises!” 
  3. The Statue-Hall 
  Opposite the entrance to Area 2 is a locked set of stone 
  double-doors to Area 6; from this same perspective there 
  is a single stone door to the right and a ten-foot-wide open 
  corridor to the left. 
   
  Floor. The chamber floor is made up of some iridescent 
  metallic material, and is highly irregular. The floor 
  is a conglomerate of square-shaped recessions and 
  recessions-within-recessions. This staggered and uneven 
  floor is difficult terrain. 
   
  Solitary stone door. The single stone door is eight 
  feet high and ten feet wide. It is meant to slide back, 
  but is caught on something. Creatures with a combined 
  Strength score of 20 or higher can force the door open; it 
  slides all the way open and reveals Area 4. A sickly stench 
  like sweat and rotting fruit emanates from the new area 
  when it opens.
   
  Hallway. The hallway leads to Area 5. The uneven 
  nature of the floor does not continue into this hallway. 
   
  Stone double doors. The double doors are sealed 
  shut. Dizzying geometric patterns on the door surround a 
  diamond-shaped recess split between the two doors; the 
  door is only opened with a fitting seal, which is currently 
  carried by Phinean in Area 5. 
   
  Once the seal is placed into this space, it splits down 
  the middle and the doors slide open, revealing Area 6. 
  Area 4. Mouthers of Madness 
  This small, pentagon-shaped chamber was a kind of 
  meditative chamber for the mad worshippers who once 
  lived here. 
   
  Gibbering mouther. Just inside the sliding stone 
  door is a gibbering mouther (MM p157), which attacks 
  immediately. Also inside the chamber with the gibbering 
  mouther are Willem’s surviving bodyguards, driven insane 
  by the room’s whispers (see below). The bodyguards are 
  allies of the gibbering mouther; they are immune to its 
  Gibbering and Aberrant Ground traits, but not its blinding 
  spittle. The bodyguards fight to the death, ranting 
  incoherently in slurred snippets of Deep Speech. 
   
  The bodyguards consist of 2 archers (VGtM p210) and 
  2 knights (MM p347). The knights do not have access to 
  their Leadership action. 
   
  Chamber whispers. If a creature closes itself inside this 
  room, sounds from outside the room are cut off entirely, 
  and the occupant hears faint whispers. A creature that 
  spends more than a minute in this room must make a 
  DC 14 Wisdom saving throw or gain a form of long-term 
  madness (DMG p260). 
  A rough-carved statue of a sinuous, eel-like creature rises 
  from the erratic floor of this circular, thirty-foot wide chamber. 
  Thin, tentacle-like spindles of stone radiate out from the 
  creature and attach randomly to the domed ceiling twenty 
  feet overhead. 
  
  38
  5. The Incomprehensible Chapel 
  This large room is a kind of inner sanctuary where large 
  groups of worshippers—or other creatures—could gather 
  in twisted worship. Every angle of the cyclopean walls 
  makes the room feel as though it is leaning dizzyingly 
  towards the altar at the far end of the room. Bulky, 
  irregular columns are placed asymmetrically around the 
  room. 
   
  Phinean. Phinean, a warlock of the great old one 
  (VGtM p220), is lurking in this chamber along with three 
  of his followers. A follower who accompanied Phinean 
  prayed at the shrine and was shown terrible eldritch 
  knowledge, becoming a nothic (MM p236). 
  Door seal. Phinean is carrying a diamond-shaped 
  object made of strange iridescent metal. It fits the 
  sealed double doors in Area 3. 
  6. Entrance to the Maddening Depths 
  A light emanates from the central pool in this large, 
  chamber, which is otherwise barren. The light is like 
  nothing of this world, and even attempting to identify 
  its color is a fruitless struggle. Shadows are thrown 
  onto the walls as creatures from the depths of the 
  pool rise toward its surface. 
  Rising from the pool are multiple chuul (MM p40), 
  ancient guardians of the sanctuary chamber awakened 
  by the opening of the door. 
  Depths of Madness. Diving into the central pool 
  reveals it is actually a brightly lit shaft with no discernible 
  bottom. Somewhere several hundred feet down, the 
  water-filled tunnel becomes a tunnel to a portion of the Far 
  Realm. As a creature who is not an aberration attempts 
  to swim down into this area, it faces progressively harder 
  saving throws to avoid a random form of short-term 
  madness as described in the Dungeon Master’s Guide. A 
  creature at a depth of 50 feet or less must make a DC 10 
  Wisdom saving throw to avoid this madness. For every 
  50 additional feet of depth, a creature must repeat the 
  saving throw, and each time the DC increases by 4. 
  Adjusting this Encounter
  Here are some suggestions for adjusting this  
  encounter, according to your group. These are not 
  cumulative.
  • 
  Very Weak: 1 warlock, 1 nothic
  • 
  Weak: 1 warlock, 2 nothics
  • 
  Strong or Very Strong: 1 warlock, 4 nothics
  Adjusting this Encounter
  Here are some suggestions for adjusting this  
  encounter, according to your group. These are not 
  cumulative.
  • 
  Very Weak: 1 gibbering mouther, 1 knight, 1 archer
  • 
  Weak: 1 gibbering mouther, 1 knight, 2 archers  
  • 
  Strong: 1 gibbering mouther, 2 knights, 3 archers 
  • 
  Very Strong: 1 gibbering mouther, 3 knights, 3 
  archers 
  Adjusting this Encounter
  Here are some suggestions for adjusting this  
  encounter, according to your group. These are not 
  cumulative.
  • 
  Very Weak: 2 chuul, 1 nothic
  • 
  Weak: 3 chuul, 1 nothic
  • 
  Strong:  3 chuul, 3 nothics
  • 
  Very Strong: 3 chuul, 4 nothics
  
  39
   Treasure. The chuul, the room, and the pool are 
  devoid of treasure. After this chamber is opened, one 
  party member of your choice finds a small object among 
  their possession; the Icon of Xxiphu. 
  Icon of Xxiphu
  Wondrous item, very rare
  This appears to be a small, thin icon of an obelisk 
  made of some strange, iridescent metal. A creature in 
  possession of this object can use it to cast the contact 
  other plane spell. Casting the spell in this manner places 
  the creature in contact with an aboleth in the ancient 
  city of Xxiphu, which answers questions to the best of 
  its considerable knowledge. The creature using the 
  icon of Xxiphu is unaware of who or what is 
  answering its questions. Once 
  the icon of Xxiphu has been 
  used in this manner, it cannot be 
  activated again for 7 days. 
  
  40
  Of Two Minds
  The adventure location is designed for 4-6 characters of 
  level 8 (Tier 2, APL 8).
  Adventure Background
  Psytatosk, an ulitharid, and a group of loyal illithid 
  broke away from their elder brain two years ago. After 
  traveling to Skullport in search of a place to begin a 
  new colony, Psytatosk approached Halaster and offered 
  to defend Undermountain in exchange for a space to 
  use as a laboratory. Halaster agreed to the proposal for 
  inscrutable reasons of his own. In addition to making 
  worthy guardians, the illithids also provide Halaster with 
  information about the wider world, taken from the brains 
  they devour.
  Psytatosk believes their former elder brain was too 
  passive in ushering in a new Illithid Empire. The 
  ulitharid is obsessed with researching ancient illithid 
  history, hoping to uncover a secret to help rebuild the 
  empire. Recently, Psytatosk’s enclave captured Jooloch, 
  an aboleth who resided in the Underdark. Psytatosk 
  hopes to break into the aboleth’s consciousness, gaining 
  access to its undying ancestral memories. After gaining 
  this knowledge, the ulitharid plans to relocate to a new 
  domain and evolve into an elder brain, creating a colony 
  that will bring about the New Illithid Empire.
     
  Adventure Overview
  The characters find Psytatosk’s lair in Undermountain. 
  While exploring the illithid enclave, the characters learn 
  about strange mind-flayer experiments and have the 
  opportunity to interact with a githzerai monk. Finally, the 
  characters face Psytatosk, engaged with Jooloch. In the 
  process the characters may make an unlikely ally as the 
  two psions are locked in a standstill.
  Adventure Hooks
  Skullport Rumormonger
  In one of Skullport’s shady taverns, a goblin beggar 
  approaches the characters. For a few coppers, she 
  says she saw “tentacle-faced weirdos” dragging a giant 
  “toothy eel” through Skullport. They were headed toward 
  Undermountain.
  Empty-Headed Adventurer
  The characters come across a dead half-orc adventurer. 
  Whatever killed him tore off the top of his skull; there’s 
  nothing inside! A tiny blood trail leads further into the 
  dungeon.
  Undermountain Enclave
  The mind flayers have claimed a small corner of 
  Undermountain and turned it into a horrific laboratory. 
  The area is bisected by a large chasm that leads deeper 
  into undeveloped sections of Mount Waterdeep. The 
  illithid make regular excursions into the surrounding 
  halls, searching for food and new thralls. The tight 
  confines means they cannot keep many slaves and their 
  experiments must be tightly controlled.
  1. Cries for Help
  As the characters approach the enclave, read or 
  summarize:
  The mind flayers have set a trap to lure unwary 
  adventurers. In order to open the gates leading to the 
  prisoners, two characters with at least 9 Strength each 
  must pull and hold a lever near each gate. The gates 
  In the distance you see a wooden door slightly ajar. No 
  light comes from beyond. A hushed cry calls out, “Help! 
  Help us! Something horrible has taken us.”
  The door moans as it opens, centuries of wear shouldered 
  on its rusted hinges. The small square chamber, void of any 
  decoration, smells sanitary. The hairs on the back of your neck 
  stand on end as the darkness seems to creep out of the lair.
  General Features
  Sights, Sounds, and Smells. The enclave is kept 
  meticulously clean and well-organized. Strange implements 
  used to dissect and study living creatures can be found 
  throughout the area.
  The area is silent other than a distant shuffling as mind 
  flayers move about. The illithids communicate with one 
  another and their thralls telepathically at all times.
  The enclave smells chemically sanitized.
  Doors and Walls. Unless noted otherwise, all doors are 
  made from iron-reinforced wood (AC 16, 20 hit points). 
  Doors are unlocked unless noted otherwise.
  Unless noted otherwise, all walls are made from 5-foot 
  thick smooth stone masonry (AC 17, 50 hit points per 
  5-foot cube) and are 10-feet tall.
  Lighting. The enclave is unlit at all times. The illithids 
  and their thralls rely on darkvision to see.
  
  41
  
  42
  remain open as long as each lever is held in place.
  The levers can be jammed in place with a metal 
  implement, such as a crowbar or piton, with a successful 
  DC 12 Strength check. A character can lift the heavy 
  iron gates with a successful DC 20 Strength check.
  The prisoners are restrained in fake manacles 
  anchored to the wall. An attempt to open the manacles 
  with a Dexterity check using thieves’ tools automatically 
  succeeds. A character who succeeds on a DC 13 
  Intelligence (Investigation) check realizes the manacles 
  are fake. The prisoners can free themselves using an 
  action.
  Creatures. The prisoners are controlled by intellect 
  devourers (MM p191). The intellect devourers are in 
  telepathic communication with the mind flayer (MM 
  p222) in Area 2 (see below). The prisoners are veterans 
  (MM p350), armed only with one dagger each. Add the 
  following Actions to their stat block:
  • 
  Multiattack. The veteran makes two melee dagger 
  attacks and one unarmed strike.
  • 
  Dagger. Melee or Ranged Weapon Attack: +5 to 
  hit, reach 5 ft. or range 20/60 ft., one target. Hit: 5 
  (1d4 + 3) piercing damage.
  • 
  Unarmed Strike. Melee Weapon Attack: +5 to hit, 
  reach 5 ft., one target. Hit: 4 bludgeoning damage.
  The prisoners claim they were captured by strange 
  aliens and their companions taken deeper into 
  the lair. If pressed for information, the prisoners 
  promise to explain the details once they have 
  freed their friends. A character who succeeds 
  on a DC 15 Wisdom (Insight) check senses 
  a lie.
  Tactics. If the intellect devourers 
  lure a few characters into their cells, 
  they send a telepathic message 
  to the mind flayer in Area 2. The 
  mind flayer enters after 2 rounds, 
  targeting any character holding a 
  lever with Mind Blast. The intellect 
  devourers teleport out of their host 
  bodies and attack, attempting to use Body Thief on a 
  low Intelligence character trapped in the cell.
  If the characters attack the prisoners before the mind 
  flayer arrives, the intellect devourers fight until the hosts 
  are killed. Then they Disengage toward area 2, where 
  they Hide and ambush the characters.
  2. Interrogation Chamber
  The mind flayers use this area to interrogate 
  captives, determining whether they make 
  better thralls or meals. The chasm 
  leads 800 feet down into the depths of 
  Undermountain. A rope bridge used to 
  span the chasm, but Psytatosk had it 
  removed, ordering the illithids to use 
  levitate to pull themselves along. 
  The trash chute in the floor leads to 
  Area 7 (see below).
  The characters can climb along 
  the eastern wall of the chasm with 
  a successful DC 13 Strength 
  (Athletics) check.
  Creatures. Unless it was 
  drawn to Area 1, there is a mind flayer (MM 
  p222) in this room. The illithid wears a flowing 
  black dress, ornamented with bloodstained tools 
  Adjusting this Encounter
  Here are some suggestions for adjusting this  
  encounter, according to your group. These are not 
  cumulative.
  • 
  Very Weak: Replace the prisoners with thugs (MM 
  pg 350). Reduce the mind flayer’s hit points by 30.
  • 
  Weak: Reduce the veterans’ hit points by 20 each. 
  Reduce the mind flayer’s hit points by 20. 
  • 
  Strong: Increase the veterans’ hit points by 10 
  each. Increase the mind flayer’s hit points by 10. 
  • 
  Very Strong: Increase the veterans’ hit points by 
  15 each. Increase the mind flayer’s hit points by 
  20. Increase the Wisdom (Insight) DC to 17
  Along the wall of this small chamber are two heavy 
  iron chairs. Leather straps hang loosely from one. In the 
  other is a half-elven man, his face blank and eyes soulless, 
  staring into the dark. Serrated hooks, scalpels, and other 
  medical instruments hang from the walls in neat rows. 
  The floor ends abruptly in a natural chasm, diving deep 
  into the mountain.
  
  43
  hanging from the belt sash. It is interrogating a half-elven 
  adventurer, whose mind is shattered. The mind flayer 
  attacks the characters on sight.
  The half-elven adventurer was being made a thrall. 
  He retains none of his former personality or memories 
  and simply stares blankly at the characters. If greater 
  restoration is cast on the half-elf for three consecutive 
  days, he regains his personality and may become an 
  ally. A character who succeeds on a DC 18 Intelligence 
  (Arcana) check understands how to cure the thrall-to-be.
  Tactics. The mind flayer attempts to stun as many 
  characters as possible with Mind Blast. If any characters 
  succeed their saving throw, the mind flayer casts 
  dominate monster on the most heavily-armed character, 
  ordering the character to defend it. The illithid prefers 
  spellcasters’ brains.
  If reduced to half or fewer hit points, the mind flayer 
  casts levitate on itself and floats above the open pit. The 
  mind flayer fights to the death and pursue the characters.
  Treasure. The mind flayer interrogator has not 
  completely stripped the half-elf. If the characters search 
  through his belt pouch, they find 20 gp, a small ruby 
  worth 125 gp, and a potion of greater healing.
  The mind flayer carries a key to Area 3C.
  3. Illithid Living Quarters
  Each of these five rooms serve as living quarters for 
  individual mind flayers. They pursue personal research 
  projects and store their thralls here when they are not 
  out on excursions. Each room is joined together by a 
  series of small tunnels in the ceiling, carved by duergar 
  thralls. The mind flayers use their levitate ability to easily 
  traverse to other quarters.
  All of the doors into the living quarters are locked; each 
  mind flayer carries the key to their own room. The doors 
  can be opened with a successful DC 15 Dexterity check 
  using thieves’ tools or forced open with a successful DC 
  16 Strength check. The latter causes enough noise to 
  alert the entire dungeon.
  The floor in each room contains a trash chute, leading 
  to Area 7.
  3A. Nascent Research
  This room is filled with jarred fetuses from a dozen 
  different humanoid species. A character who passes 
  a DC 16 Intelligence (Nature) check realizes some of 
  the specimens are not from Toril. There are abundant 
  scientific drawings of young children and adolescents.
  3B. Maritime Pursuits
  There are star charts, astrolabes, and other navigation 
  tools neatly organized throughout the room. A large glass 
  jar contains a murky green-brown liquid and a severed 
  human head, perfectly preserved. It is humming a sea 
  shanty. If the characters unstopper the jar, the head begins 
  merrily singing the tune. It only knows the one song and 
  does not answer questions or engage in conversation.
  Creatures. A mind flayer (MM p222) is asleep in 
  this chamber. It makes Wisdom (Perception) checks 
  at disadvantage, but awakens if there are loud noises 
  in its quarters. If the characters wake the illithid, it 
  telepathically calls for help from its ally in Area 3E.
  Psionics and Counterspell
  Remember, that in order to counterspell a spell, you must 
  be able to perceive it being cast. Because a mind flayer 
  casts spells without using any components, they cannot be 
  countered. They are still subject to dispel magic, however.
  As you settle along the far side of the chasm, you see 
  a serpentine hallway stretching into the darkness. Doors 
  break up the cold expressionless stone walls to the east. 
  The dark, cold hall is made all the more unsettling as 
  you notice someone humming a tune at the edge of your 
  perception.
  Adjusting Any Single Mind Flayer Encounter
  Here are some suggestions for adjusting this  
  encounter, according to your group. These are not 
  cumulative.
  • 
  Very Weak: Reduce the mind flayer’s hit points by 
  30.
  • 
  Weak: Reduce the mind flayer’s hit points by 20. 
  • 
  Strong: Increase the mind flayer’s hit points by 20.
  • 
  Very Strong: Increase the mind flayer’s hit points 
  by 30.
  This adjustment block should be considered when 
  running any encounter with a single mindflayer. Extreme 
  care should be taken running encounters with multiple 
  mind flayers!
  
  44
  3C. Ancient History
  This chamber is lined with bookcases full of elven lore. 
  The small desk contains the illithid’s work in progress: 
  a translation guide between the illithids’ psionically 
  resonant language, Qualith, and Elven.
  Treasure. If the characters succeed on a DC 16 
  Wisdom (Perception) check, they find a pair of boots 
  of elvenkind in a small bookcase drawer. Elves have 
  advantage on this ability check.
  3D. The Science of Chance
  This illithid is obsessed with the similarities in games 
  of chance. The room is littered with dice, cards, and 
  boardgames.
  3E. New Pets
  This chamber smells of embalming fluids and fresh 
  blood. Preserved dogs, cats, birds, and small rodents line 
  the walls in cases. The illithid here is researching how 
  to create a new species of psionically enhanced beast, 
  similar to the cranium rat.
  Creatures. A mind flayer (MM p222) is here dissecting 
  an animal. It attacks the characters on sight.
  4. Psytatosk’s Private Chambers
  These two conjoined rooms are Psytatosk’s quarters.
  The door is locked and can be opened with a successful 
  DC 15 Dexterity check using thieves’ tools or forced 
  open with a successful DC 16 Strength check. The latter 
  causes enough noise to alert the entire dungeon.
  Creatures. 3 enthralled quaggoths (MM p256), guard 
  the area. They attack the characters on sight and fight to 
  the death. They do not leave Psytatosk’s quarters.
  A githzerai monk (MM p161) is held captive in a 
  cage made of psionic energy. It acts as a forcecage spell, 
  but can be dispelled as if it were a 7th-level spell. If the 
  characters succeed on a DC 18 Intelligence (Arcana) 
  check to rearrange the crystal matrix powering the cage, 
  it is deactivated. If a character fails the check by 5 or 
  more, they take 11 (2d10) psychic damage.
  The door opens to reveal a pair of small rooms. The 
  first is dominated by a cage made of shimmering blue-
  green light. A complex matrix of purple crystals float four 
  feet off of the ground, hovering in front of the prison. 
  Inside is an alien female, her emaciated body covered in 
  scars and burns. She presses her back against the far side 
  of the cage, her eyes wide with terror and madness.
  In the room beyond, you see a beautiful oaken bed, 
  clearly crafted by elven hands. A curio cabinet containing 
  fine crystal glasses and rare wines stands alongside 
  a small table and plush velvet chairs. Red, gleaming 
  eyes peer out of the darkness as musclebound, shaggy, 
  creatures rush you.
  
  45
  The githzerai monk, called Arwah, currently has 15 
  hit points and is on the verge of insanity. Although she 
  knows Common, she speaks only in faltering Gith until 
  her madness is cured. Her body is covered in scars and 
  cauterized wounds. Characters who succeed on a DC 
  13 Wisdom (Medicine) check know that she has been 
  operated on many times. She only speaks to the characters 
  if they calm her, either momentarily with a successful DC 
  18 Charisma (Persuasion) check or permanently by 
  casting lesser restoration. See Roleplaying Arwah for 
  more information.
  Developments. If the characters spend 10 minutes 
  searching the area, they find a smooth stone tablet carved 
  in Qualith and three black iron spikes, 4-inches long and 
  2-inches in diameter. If a character touches the tablet 
  while under the effects of a comprehend languages spell 
  or similar effect, they understand enough of the alien 
  language to determine the spikes, when carefully driven 
  into a thrall’s skull, prevent them from being psychically 
  influenced by anyone but their master. Psytatosk uses 
  these creations to protect his thralls from the aboleth.
  If the characters cure and ally with Arwah, she tells the 
  characters about the aboleth and Psytatosk’s plans. She 
  fights alongside the characters against Psytatosk. If she 
  survives, she might remain loyal to the party or offer a 
  reward, at your discretion.
  5. Brain Library
  As the characters enter, read or summarize:
  Mind flayers do not keep libraries of books or even 
  Qualith infused tablets. Instead, they store the brains 
  of particularly intelligent creatures for prolonged study. 
  When an illithid devourers a creature’s brain, it acquires 
  faint memories from the victim, but by preserving valuable 
  brains, the colony can harvest deeper knowledge.
  Using the Library. If the characters succeed on a 
  DC 20 Intelligence (Arcana) check to understand how 
  to use the library, they can read any number of brains 
  in the collection. If Arwah is present and her madness 
  cured, she shares her knowledge of illithid lore, granting 
  advantage on the ability check. After selecting a brain, the 
  character must succeed on a DC 14 Intelligence saving 
  Roleplaying Arwah
  Use these notes to help bring Arwah to life if the characters 
  cure her madness.
  Background. Just before leaving the elder brain, Psytatosk 
  led an attack against a githzerai monastery on the plane of 
  Limbo. The ulitharid and its followers slaughtered many of 
  the monks, but Psytatosk chose to capture Arwah. She has 
  been a personal experiment for several years and bears all of 
  the physical and emotional scars that brings.
  Traits. Arwah is perfectly calm at all times. She often 
  quotes Zerthimon.
  Ideal. Order. The mind and body must be well-ordered to 
  grow.
  Bond. The teachings of Zerthimon must be told to every 
  world.
  Flaw. I become frustrated with less enlightened races.
  This circular chamber contains dozens of glass jars 
  suspended from the ceiling on retractable chains. Inside 
  each jar is a humanoid brain, floating in a clear viscous 
  liquid.
  An illithid and its brawny thralls stand in the center 
  of the room. The mind flayer is carefully handling a 
  brain, turning it over in its hands while wearing strange 
  leather gloves, a pulsating red crystal set into each palm. 
  Tendril-like probes snake up from the gloves, attaching to 
  the illithid’s head. As it notices you, it throws down the 
  brain with a sickening squelch and reaches for a curved 
  crystalline blade.
  Adjusting this Encounter
  Here are some suggestions for adjusting this  
  encounter, according to your group. These are not 
  cumulative.
  • 
  Very Weak: Reduce the quaggoths’ hit points by 20 
  each.
  • 
  Weak: Reduce the quaggoths’ hit points by 10 each.  
  • 
  Strong: Add 1 quaggoth thonot (MM p256).
  • 
  Very Strong: Add 1 quaggoth thonot (MM p256) 
  and increase the quaggoths’ hit points by 10 each.
  
  46
  throw or take 11 (2d10) psychic damage and be unable 
  to use the library for 24 hours.
  The machine allows the user to read a brain as if it 
  were affected by a deep detect thoughts spell. The brain 
  reveals only factual information it knew in life and cannot 
  hide or distort memories. The machine also brings 
  forward subconscious memories the living person may 
  have thought they had forgotten.
  You may populate the library with as many brains as you 
  would like. This provides an opportunity for you to share 
  more information about Undermountain, Waterdeep, 
  or your campaign as a whole. Here are a few brains the 
  party might find:
  Valiant Harper. An elven Harper and her dwarven 
  friend ventured into Undermountain to find a lost temple 
  of Dumathoin. They were attacked by the mind flayers 
  before discovering the temple. The Harper held a hallway, 
  allowing her companion to escape.
  Foolish Thayan. Psytatosk enticed a Red Wizard of 
  Thay to visit the enclave, promising the illithids would 
  purchase his magic items. The ulitharid valued the 
  wizard’s knowledge, so he kept it.
  Agent of Xanathar. The illithid enclave ran afoul with 
  Xanathar’s Thieves’ Guild soon after arriving in Skullport. 
  Psytatosk acquired a captain’s brain, which he uses to 
  learn more about the Waterdhavian underworld.
  Creatures. A mind flayer psionic warrior (see 
  below) and its thralls, 2 quaggoths (MM p256) are in 
  this chamber. The illithid is using a strange machine to 
  connect with a preserved brain. The machine is worn on 
  the hands like a pair of gloves, which have six probes that 
  connect to the user’s head. The illithid is delicately holding 
  a brain, turning it over slowly. When it perceives the 
  characters, it disconnects the machine (requiring 
  no action) and attacks with its thralls. The mind 
  flayer and its thralls fight to the death and 
  pursue the characters.
  Treasure. The mind flayer carries a key 
  to Area 3D. The mind blade (VGtM p81) 
  can only be attuned to by the mind flayer, 
  but is worth 400 gp to the right buyer.
  6. Psytatosk’s Laboratory
  As the characters enter, read or summarize:
  This is Psytatosk’s laboratory, where it conducts 
  psychic experiments on a variety of subjects, all 
  in an attempt to learn more about the ancient 
  Illithid Empire. The large domed structure will 
  serve as its brine pool after it evolves into an 
  elder brain. The walls in this chamber are 30 
  feet tall.
  Creatures. Psytatosk, an ulitharid (VGtM 
  p175), is on the balcony 15 feet above the 
  ground, overlooking the laboratory. There 
  Adjusting this Encounter
  Here are some suggestions for adjusting this  
  encounter, according to your group. These are not 
  cumulative.
  • 
  Very Weak: Remove 1 quaggoth and reduce the 
  mind flayer’s hit points by 20.
  • 
  Weak: Remove 1 quaggoth. 
  • 
  Strong: Add 1 quaggoth. 
  • 
  Very Strong: Add 1 quaggoth and increase the mind 
  flayer’s hit points by 20.
  This large chamber’s vaulted ceilings tower above you. 
  Workbenches, chairs used to restrain captives, and a 
  pristine operating table decorate the area. In the center 
  of the laboratory is a captive monster, a large aquatic 
  creature resembling an eel with a lamprey-like mouth and 
  long tentacles. An illithid stands near the cage, whipping 
  the creature with a glowing lash. Armed grey dwarves 
  watch with blank stares, iron spikes protruding from the 
  base of their necks. Along the western wall is a large 
  domed carriage made of black wrought iron stylized with 
  vicious, slender barbs. The glass dome is filled with fluid. 
  It floats several inches off the ground.
  Standing above the scene on a balcony is a towering 
  illithid, its mass of tentacles reaching to the ground. You 
  feel a presence subtly enter your mind like a light caress 
  on the back of your neck. The illithid’s tentacles twitch 
  as the floor and walls shudder, reverberating with psionic 
  power. Another force invades your thoughts, this one akin 
  to a club over the head. “Kill them, you fools, and the 
  world’s riches are yours!”
  
  47
  are no stairs or ladders leading to the balcony, but the 
  pillars can be climbed with a successful DC 12 Strength 
  (Athletics) check. An assistant, a mind flayer (MM 
  p222) armed with a mind lash, is on the ground floor, 
  whipping the aboleth through its psionic cage. Add the 
  following Action to the mind flayer’s stat block:
  Mind Lash. Melee Weapon Attack: +4 to hit, reach 
  10 ft., one target. Hit: 2 (1d4) slashing damage plus 5 
  (2d4) psychic damage. Any creature that takes psychic 
  damage from the mind lash must also succeed on a 
  DC 15 Wisdom saving throw or have disadvantage on 
  Intelligence, Wisdom, and Charisma saving throws for 
  1 minute. The creature can repeat the saving throw at 
  the end of each of its turns, ending 
  the effect on 
  itself on a success.
  Psytatosk’s most prized thralls, 
  3 duergar (MM p122), stand 
  guard on the ground floor. Each 
  duergar has a black iron spike, like 
  those found in area 4, driven 
  into the base of their skull. If 
  a character spends an action 
  and succeeds on a DC 16 
  Strength check to remove 
  the spike, the duergar is 
  incapacitated until the end of 
  their next turn. While the spikes 
  are in place, the duergar are immune 
  to the illithids’ Mind Blast as well as 
  the aboleth’s Enslave ability.
  Jooloch, an aboleth (MM p13), is 
  captured in a psionic cage like the one found in Area 
  4. This cage, however, is maintained by Psytatosk’s own 
  psionic energy and counts as a 9th-level spell for the 
  purposes of dispel magic. The aboleth cannot make 
  tentacle attacks outside of the cage. 
  Make the following changes to Jooloch’s stat block:
  • 
  It currently has 35 hit points.
  • 
  Remove all Legendary and Lair Actions.
  Tactics. Psytatosk attempts to keep the characters 
  at bay using Mind Blast and telekinesis. If a character 
  makes it onto the balcony, the ulitharid uses levitate to 
  float above combat. If a character is psionically weakened 
  by the mind lash, Psytatosk attacks them, attempting to 
  extract their brain.
  The mind flayer assistant uses Mind Blast and attacks 
  with their mind lash, weakening targets for Psytatosk. It 
  attempts to dominate particularly oafish characters.
  The duergar Enlarge themselves and engage in melee 
  combat, protecting their illithid masters.
  The mind flayer and duergar fight to the death and 
  pursue the characters. Psytatosk plane shifts to the 
  Astral Plane if brought below 15 hit points.
  Unlikely Ally. Jooloch telepathically contacts the 
  characters when they enter, promising great wealth if 
  they help the aboleth. If they respond, Jooloch tempts 
  them with their greatest desires, using its Probing 
  Telepathy trait. It says that it cannot 
  feel the duergar’s minds and the 
  illithid are too strong to enslave. 
  If it were able to sense the 
  duergar, it could turn them 
  against their masters.
  If the characters remove the iron 
  spikes from a duergar, Jooloch 
  uses Enslave on it. The duergar 
  automatically fail their saving throw 
  versus this effect.
  Treasure. Psytatosk carries 
  a key to Area 4. It also carries a 
  small round stone made up of 
  a series of interlocking circles, 
  each 
  of 
  which 
  moves 
  independently. 
  The 
  item 
  is called The Unbroken Circle of 
  Zerthimon, and serves as the githzerai’s religious text. 
  Within the teachings are several magical inscriptions 
  written in Gith. These inscriptions function as spell 
  scrolls, including: sanctuary, lesser restoration, see 
  invisibility, and mind blank. It also contains a scroll of 
  protection against aberrations.
  The assistant carries a key to Area 3A. The mind lash 
  is worth 200 gp to the right buyer.
  Developments. If Psytatosk was able to plane shift to 
  safety, it abandons its pursuits in Undermountain but 
  becomes obsessed with the characters, vows to consume 
  
  48
  each of their brains, and becomes a recurring villain.
  If Arwah is present, she requests The Unbroken Circle 
  of Zerthimon; it was her master’s text from which she 
  was taught.
  If the characters attempt to help Jooloch and do not kill 
  the aboleth, it sends a minion to the characters in two 
  days. Ask a player who was helpful to the aboleth which 
  Rare magic item they would like from the Dungeon 
  Master’s Guide. The minion delivers the item alongside 
  a giant pearl worth 900 gp.
  7. Trash Collection
  Several locations in the enclave contain trash chutes 
  that lead to this refuse pit. Each chute is sloped, leading 
  80 feet down, and slick with blood, ooze, and other 
  fluids. If the characters climb down the chutes, they 
  must succeed on a DC 14 Strength (Athletics) check. 
  If a character fails, they slip and roll down the chute, 
  taking 10 (3d6) bludgeoning damage, landing prone in 
  the pit. If a character falls, the sounds can be heard in 
  any room with a trash chute, potentially alerting enemies. 
  Anchoring a rope at the top of the chute grants advantage 
  on this ability check.
  The refuse pit is filled with nearly 2 feet of standing 
  water. The area counts as difficult terrain for creatures 
  without a swim speed.
  Creatures. The illithids’ strange experiments produce 
  equally strange and dangerous byproducts. 2 gibbering 
  mouthers (MM p157), spawned from the terrified psychic 
  resonance of the illithids’ victims, are in the pit, waiting to 
  devour a new failed experiment.
  Treasure. If the characters search the area and succeed 
  on a DC 16 Wisdom (Perception) check, they find a 
  bandolier of potions, including: 3 potions of healing, a 
  potion of poison resistance, a potion of water breathing, 
  and a potion of heroism. They also find a ring of spell 
  storing. It is currently storing mirror image and shield.
  Adjusting this Encounter
  Here are some suggestions for adjusting this  
  encounter, according to your group. These are not 
  cumulative.
  Very Weak and Weak: Reduce the gibbering mouthers’ hit 
  points by 15 each.
  Strong and Very Strong: Add 1 gibbering mouther.
  Adjusting this Encounter
  Here are some suggestions for adjusting this  
  encounter, according to your group. These are not 
  cumulative.
  • 
  Very Weak: Remove 1 duergar and reduce the 
  mind flayer’s hit points by 20. Reduce Psytatosk’s 
  hit points by 40 and reduce all of its DCs to 15.
  • 
  Weak: Remove 1 duergar and reduce the mind 
  flayer’s hit points by 20. Reduce Psytatosk’s hit 
  points by 40
  • 
  Strong: Add 1 duergar.
  • 
  Very Strong: Add 1 duergar and increase the mind 
  flayer’s hit points by 20.
  As you peer down the chute, a strong acrid odor wafts 
  up, cinging your nostrils. The smell of decay stands in stark 
  contrast to the pristine lair. Blood, bile, and a thick ooze 
  coat the chute.
  
  49
  Mind Flayer Psionic Warrior
  Medium aberration, lawful evil
  Armor Class 16 (brestplate)
  Hit Points 104 (16d10+16)
  Speed 30 ft.
  STR
  DEX
  CON
  INT
  WIS
  CHA
  12 (+1) 16 (+3) 12 (+1) 19 (+4) 17 (+3) 17 (+3)
  Saves Dex +6, Int +7, Wis +6
  Skills Acrobatics +6, Arcana +7, Deception +6, Insight +6, 
  Perception +6, Stealth +6
  Senses darkvision 120 ft., passive Perception 16
  Languages Deep Speech, Telepathy 120 ft., Undercommon
  Challenge 8 (3,900 XP)
  Magic Resistance. The mind flayer has advantage on saving 
  throws against spells and other magical effects.
  Innate Spellcasting (Psionics): The mind flayer is an 8th-level 
  spellcaster. Its innate spellcasting ability is Intelligence (spell 
  save DC 15). It can innately cast the following spells, requiring 
  no material components:
  At will: detect thoughts, levitate
  1/day each: dominate monster, plane shift (self only)
  Spellcasting (Psionics): The mind flayer is an 8th-level spell-
  caster. Its spellcasting ability is Intelligence (spell save DC 15, 
  +7 to hit with spell attacks). It can cast the following spells, 
  requiring no material components:
  At will: guidance, mage hand, true strike, vicious mockery
  1st level (4 slots): charm person, command, sanctuary, shield
  2nd level (3 slots): crown of madness, phantasmal force, see 
  invisibility
  3rd level (3 slots): clairvoyance, fear, haste
  4th level (2 slots): compulsion, confusion 
  Actions
  Multiattack. The mind flayer makes three attacks with its 
  mind blade.
  Mind Blade. Melee Weapon Attack: +6 to hit, reach 5 ft., one 
  target. Hit: 6 (1d6 + 3) slashing damage plus 7 (2d6) psychic 
  damage.
  Tentacles. Melee Weapon Attack: +7 to hit, reach 5 ft., one 
  creature. Hit: 15 (2d10 + 4) psychic damage. If the target is 
  Medium or smaller, it is grappled (escape DC 15) and must 
  succeed on a DC 15 Intelligence saving throw or be stunned 
  until this grapple ends.
  Extract Brain. Melee Weapon Attack: +7 to hit, reach 5 ft., one 
  incapacitated humanoid grappled by the mind flayer. Hit: 
  The target takes 55 (10d10) piercing damage. If this damage 
  reduces the target to 0 hit points, the mind flayer kills the 
  target by extracting and devouring its brain.
  Mind Blast (Recharge 5–6). The mind flayer magically emits 
  psychic energy in a 60-foot cone. Each creature in that area 
  must succeed on a DC 15 Intelligence saving throw or take 
  22 (4d8 + 4) psychic damage and be stunned for 1 minute. A 
  creature can repeat the saving throw at the end of each of its 
  turns, ending the effect on itself on a success.
  
  50
  The Hunger of Abbathor
  The adventure location is designed for 4-6 characters of 
  level 9 (Tier 2, APL 9).
  Adventure Background
  The 
  vast 
  Melairkyn 
  clan 
  empire 
  that 
  spanned 
  Undermountain was ultimately brought down by delving 
  too deep. The Melairkyn dwarves opened up caverns in 
  the Underdark that led drow, duergar and other beasts 
  from the Night Below to their tunnels. 
  The empire didn’t fall immediately. It took decades of 
  violent war, where the dwarves slowly lost ground and 
  the invaders fortified and settled in. During those early 
  incursions, the duergar made heavy sorties into the 
  lower levels, broke into deep vaults, and carried off 
  untold treasures. In an effort to appease Abbathor, the 
  priesthood commissioned the construction of the Hunger 
  of Abbathor, a shrine and offering altar to their avaricious 
  god, using the slave labour of thousands of captured 
  Melairkyn dwarves.   
  Adventure Overview
  The characters enter the shrine and run afoul of the 
  gargantuan gelatinous cube that hibernates here.
  If the heroes reach the balcony and activate the gong 
  there, they awaken the spirits of slaves and defenders 
  alike.. Discussion with the ghosts may reveal the history 
  of the shrine, if the characters are inclined to converse.
  Approaching the statue allows internal access into the 
  head chamber, through the mouth (or the concealed 
  entrance in the helmet), and traversing the chute reveals 
  the partially collapsed treasure room and its glittering 
  guardian.    
  Adventure Hooks
  Discovery by Chance….
  The adventurers may simply stumble onto the shrine as 
  part of their travels within the halls of Undermountain.
  The Temple of Dumathoin
  If the adventurers have completed the Temple of 
  Dumathoin adventure in this book, they may have 
  discerned clues as to the shrine’s location from the library 
  there, or gained insight via the use of the Altar.
  The Lost Treasure
  Rumours circulate through the taverns of Skullport 
  about a lost duergar treasure repository. Skilled 
  investigation might piece together enough landmarks in 
  Undermountain to lead characters to the shrine.
  The Hunger of Abbathor
  1. Great Portals 
  The corridor is 30 feet high here. The arrow slits are 1 
  foot wide and will not allow passage to characters unless 
  they possess unusual magical means, such as gaseous 
  form or teleportation. 
   
  Despite the formidable-looking gates, they open 
  inward easily and silently if touched, courtesy of cunning 
  counterweights concealed in the walls. If not wedged 
  open, they swing closed of their own accord after a 
  General Features
  Terrain. The entire complex is worked stone.
  Light. There is no light anywhere except Area 4 where 
  the dim light shed by the great statue’s eyes is visible. 
  However if the characters activate the gong, Area 4 is 
  bathed in bright light and areas 2 and 3 become dim. Area 
  5 is brightly lit, and area 6 is dark. 
  Ceiling Height. Each area has its height stated under the 
  descriptions as all are different.  
  Sounds. Soft, mournful howling echoes through the 
  entire complex. It might just be the wind through the great 
  chasm, but it carries a tangible sense of melancholy and 
  aching loss.
  Unhallowed. Undead of dwarven origin cannot be turned 
  or affected by Channel Divinity abilities within the complex.  
  A pair of gargantuan iron doors block the corridor here, 
  each standing fully twenty feet high and ten wide. The 
  faces of each are etched with intricate, blocky patterns 
  reminiscent of a maze, and symbols of a dripping dagger 
  dominate the centre of each.
  Above the great portal, a half dozen arrow slits pierce 
  the angled stone wall above, though nothing can be seen 
  beyond them.  
  
  51
  
  52
  minute, but are as easy to open from either side. 
  2. First Look
  The corridor is 30 feet high here, until it reaches the 
  chasm. The archway to the north leads on to a dark 
  chamber. 
  Development. If the characters proceed to Area 3 
  without examining Area 2A, the gelatinous cube from 
  Area 2A squeezes out behind them, spans the entire 
  bridge (20 feet across) and attempts to engulf them once 
  the easy escape route has been cut off, pressing them 
  toward the great statue.  
  2a. Antechamber
   
  The chamber is a 10-foot by 10-foot square with a 
  20-foot-high ceiling. The entire space is filled with 
  a gargantuan gelatinous cube (see below).
  Remembering that this area is dark (which 
  doesn’t allow for perception checks unless 
  the characters carry their own light source), 
  the characters may not see the creature. Even 
  darkvision (which treats darkness as dim light) 
  incurs disadvantage to Perception checks if no 
  light source is present.
   
  If the characters are perceptive (passive 
  Perception 15) or thoroughly investigate before 
  advancing (DC 15 Intelligence (Investigation) check), 
  they will notice an odd distortion in the air and a few 
  objects seemingly floating in the middle of this distortion. 
  The “distortion” is the gargantuan gelatinous cube.
   
  Once the cube is dealt with, the characters can 
  discover that internally it held the bones of numerous 
  dead dwarves, some iron brackets and lanterns, a few 
  corroded axe heads, crossbow arms and bolt heads, and 
  a scattering of coins: 14gp, 27sp and 54cp. 
  2b. Balcony
   
  There are five corpses here, long dead and 
  desiccated with age. Each wears serviceable 
  chainmail, and has a battleaxe and heavy 
  crossbow (with 20 bolts), but the wood is 
  so aged that any of these weapons has a 
  50% chance of breaking each time they 
  are used. Each corpse shows no signs 
  of what killed it, and do not detect as 
  undead or the like.
  A search near the gong reveals a brass 
  striker, and it and the gong itself are in 
  Beyond the gates the tunnel continues for a short 
  distance before expanding into a massive chasm. The floor 
  continues as an open bridge across the wide gap to an 
  immense dwarven head carved from stone, hellish light 
  spilling from its eyes and open mouth.     
   
  Just to your north is an archway leading away into 
  darkness, and above you is an open balcony that opens on 
  the level of the arrow slits you saw before, as near as you 
  can tell.
  An archway leads into a dark, empty chamber that is 
  twice as tall as it is wide. 
   
  A set of stairs to your left ascends to the balcony level 
  above.
  Adjusting this Encounter
  Here are some suggestions for adjusting this  
  encounter, according to your group. These are not 
  cumulative.
  • 
  Very Weak: Reduce the hit points of the cube by 
  50, and the ability save DCs by 2
  • 
  Weak: Reduce the hit points of the cube by 30
  • 
  Strong: Increase the hit points of the cube by 30
  • 
  Very Strong: Increase hit points to maximum (288) 
  and increase ability save DCs by 1
  A ten-foot-wide balcony overlooks the bridge on one 
  side via an open railing, and the great portals through the 
  arrow slits on the other. 
  A brass gong rests against the south wall, suspended by 
  iron chains. Across the floor are a number of desiccated 
  dwarven corpses, their weapons and armour dull with a 
  layer of dust.  
  
  53
  good condition. The gong is not magical, but if it is struck, 
  the sound reverberates throughout the area, acting as 
  both an alarm and a call to the spirits of the dead that 
  are still connected to this place. Read or paraphrase the 
  following:
   Six spirits break off from the rest and move with 
  purpose toward the balcony. One halts near you, its 
  ghostly form showing the disapproving visage of a dwarf 
  in ethereal finery—the robes and symbol of Abbathor 
  adorn its spectral form. The other five enter the corpses, 
  which shudder and lurch to their feet, empty eyes burning 
  with eldritch fire  
   
  The spirits cannot be affected in any way until they enter 
  the corpses. They then rise as deathlock wights (MToF 
  p129) and attack the characters. The sixth spirit is the 
  ghost of Averbrel, a priest of Abbathor. Unless attacked 
  (or otherwise affected by abilities) he simply watches the 
  combat, and if the characters prevail he lets out a long 
  sigh of resignation.
   
  If questioned, Averbrel sermonizes about the history 
  of the temple, the glory days of the duergar invasion, 
  and the slow decline of the Melairkyn dwarves. He can 
  recount the hundreds of slaves captured and worked to 
  death to build this shrine, and the blessings they received 
  from Abbathor as they poured tribute into its jaws. He 
  will disclose there is a treasure chamber far below, but 
  NOT the existence of the secret door to access it or the 
  treasure guardian. Eventually he’ll ramble off into vague 
  half remembered stories and fade away.         
  3. The Bridge
   
  If the gong at Area 2B has been struck, add the 
  following;
  The bridge is structurally sound, but the lack of rails 
  and the intimidating effect from the statue combines to 
  create a sense of confusion and vertigo. Each character 
  on the bridge or statue (Areas 3, 4 and 4A) must make 
  a DC 17 Wisdom saving throw or suffer the effects 
  of a bane spell. A successful save makes the character 
  immune for 24 hours. If affected, a character remains so 
  until they leave the area, but upon returning a new save 
  is required.
   
  The chasm is around 250 feet across at this point, and 
  several miles in length and depth. Peering over the edge 
  characters can see the body of the statue disappear into 
  the darkness. If they possess extraordinary means of 
  discernment, the statue is 250 feet tall, and stands on 
  a massive pillar that reaches several miles downward, 
  not meeting anything else until it reaches a river at the 
  chasm’s base. Around 300 feet down and on the rear 
  of the pillar is access to Area 6 and 6A. Attempting to 
  climb the statue requires a DC 15 Strength (Athletics) 
  check. 
  As the brassy sound of the gong reverberates throughout 
  the area, pale ghostly spirits begin to fade into view. A few 
  at first, then suddenly hundreds, these shades resemble the 
  spirits of dwarves. They slowly drift around the chasm as if 
  lost or confused, filling the area with a mournful wail that 
  can no longer be mistaken for rushing wind.
  Adjusting this Encounter
  Here are some suggestions for adjusting this  
  encounter, according to your group. These are not 
  cumulative.
  • 
  Very Weak: Replace deathlock wights with standard 
  wights (MM p300)
  • 
  Weak: Reduce the hit points of each deathlock wight 
  by 10 
  • 
  Strong: The deathlock wights have maximum hit 
  points (55)
  • 
  Very Strong: Replace one of the wights with a 
  deathlock mastermind
  The wide stone bridge stretches forth into the vast 
  chasm, reaching out to the gargantuan statue of Abbathor. 
  The vastness of the chasm—of which you can see neither 
  the bottom nor the far side—and the lack of railings makes 
  the span feel flimsy despite its sturdy construction.
  Ahead, the huge visage of Abbathor glares at you with a 
  hungry expression, the light emanating from its eyes and 
  mouth giving it an imposing demeanor.  
  Translucent spirits drift aimlessly around the chasm. As 
  you begin to cross the bridge they drift over, observing you 
  from a distance. They all appear to be gaunt dwarves with 
  melancholy expressions, their soulless gazes following your 
  progress impassively. 
  
  54
  4. The Hunger
   
   
  The mouth rests just above ground level, and the 
  chute within is 5 feet high with an open top and a slick 
  surface, angled at 35 degrees downward. It ends in a 
  vertical shaft. A chamber can be seen at the 
  level of the top of the chute. Anyone 
  attempting to us the chute to 
  gain entry must make a DC 
  17 Dexterity check or slip 
  on the slick surface, sliding 
  into the 300 foot drop to 
  Area 6 (and likely death 
  if they have no way to 
  arrest their fall, taking 
  1d6 bludgeoning damage 
  for every 10 feet fallen, to 
  a maximum of 20d6). 
   
  The crystal eyes are 
  10 feet above the bridge 
  level 
  and 
  cannot 
  be 
  damaged, but they can 
  be used to view Area 5 
  in enough detail to use 
  teleportation-type abilities 
  to enter.
  4a. Secret Door
   
  If the characters climb onto the northernmost pauldron 
  (requiring a DC 12 Strength (Athletics) check), they may 
  be able to find a secret door set into the side of the helmet 
  that gives safe access to Area 5. The door is cunningly 
  wrought, and requires a DC 18 Wisdom (Perception) 
  check to discover. 
  5. The Head Chamber
   
  On a closer examination, the carvings mimic the 
  patterning of a brain, with lines and ridges, 
  but these in turn are embedded 
  with dwarven runes that recite 
  scripture of the church of 
  Abbathor. Anyone praying, or 
  contemplating 
  the 
  pattern 
  or scripture, must make a 
  DC 15 Charisma saving 
  throw. Success grants the 
  character insight into the 
  nature of avarice, allowing 
  advantage on attack rolls 
  and saving throws against 
  the treasure golem in Area 
  6. Failure means that the 
  character is consumed 
  by greed, and gains the 
  following Flaw: 
  Greed – I am more 
  deserving of wealth than 
  any other. What I want, I 
  should have.    
  The flaw can only be removed 
  with a remove curse or wish spell.
   
  The chute is detailed in Area 4, and the shaft plunges 
  300 feet to Area 6. The room, chute, and shaft are all 
  smooth-sided, offering no options for securing ropes 
  or climbing gear. A creature can climb the shaft on a 
  successful DC 20 Strength (Athletics) check. Failure 
  results in a fall of 300 foot drop to Area 6, taking 20d6 
  bludgeoning damage unless they have a way to arrest the 
  plummet. 
  The enormous face glares down at you, its cunningly 
  wrought, stony expression conveying contempt, avarice, and 
  endless hunger, as if the uncaring deity could consume the 
  earth itself. 
  The open eyes seem to be formed of crystal, allowing the 
  illumination from inside to spill forth, while the open maw 
  has a deep angled chute, presumably where offerings are 
  made.  
  The chamber is bathed in an orange glow that has no 
  specific source you can discern. 
  Carvings so intricate they are almost imperceptible 
  line every inch of the inner surfaces of this chamber. The 
  snaking designs are difficult to follow without becoming 
  disoriented. 
  In the center of the room a cylindrical shaft disappears 
  into darkness. It is fed on one side by a deep, angled 
  chute.
  
  55
  6. The Treasury
   
  The intact areas of the chamber are 30 feet high and 30 
  feet in diameter. 
   
  Anyone exiting the shaft in motion and not otherwise 
  tethered—including under a feather fall effect or a 
  ‘controlled’ drop from the bottom of the shaft—must 
  make a DC 14 Dexterity saving throw or slide off the 
  exposed edge on landing, falling out into the chasm and 
  the several mile drop to the river below. Anyone falling 
  completely uncontrolled at high speed makes this saving 
  throw at disadvantage. Characters that have safe footing 
  in the chamber may attempt to save a falling character by 
  making an attack roll against their AC. Success indicates 
  that the falling character has been secured. 
   
  The treasure scattered across the room includes 9694 
  gp, 12567sp and 27901cp, as well as 134 gems of varying 
  value (121x 50gp gems, 7x 100gp gems, 4x 200gp gems, 
  1x 500gp gem and 1x 1000gp gem). There are also 23 
  trinket or art objects (worth 50gp each), as well as a potion 
  of superior healing (in a metal vial), a scroll of protection 
  from fiends (in a bone scroll tube), a cloak of protection 
  and an ioun stone of awareness.      
   
  If any of the treasure is picked up, the majority of the 
  coins and gems coalesce into a treasure golem (see 
  Appendix) that seeks to destroy the thieves. 
  Development. For every round of combat in Area 6 roll 
  1d4x100. This is the value in gold pieces of treasure lost 
  as a result of damage or loss over the edge of the precipice. 
  At your discretion, clever methods of preventing loss 
  (such as putting up a wall of force) can reduce this by up 
  to half. In any case, fighting the treasure golem destroys 
  some of the treasure. Exactly how much is up to you.
  6a. The Broken Span
  20 feet from the edge of Area 6 is the sheared-off 
  remains of a bridge span that once connected to the 
  treasure chamber. The span reaches to the other side of 
  the chasm—around 100 feet at this point—then enters the 
  wall to lead deeper into another level of Undermountain.
  Adjusting this Encounter
  Here are some suggestions for adjusting this  
  encounter, according to your group. These are not 
  cumulative.
  • 
  Very Weak: Reduce the hit points of the treasure 
  golem by 50, and the ability save DCs by 2
  • 
  Weak: Reduce the hit points of the golem by 30
  • 
  Strong: Increase the hit points of the golem by 30
  • 
  Very Strong: Increase hit points to maximum (255) 
  and increase ability save DCs by 1
  The shaft pierces the ceiling of a domed chamber at its 
  apex, leaving a gap of 30 feet to the floor below. 
  At some point in time a section of the chamber collapsed, 
  leaving half the chamber open and exposed to the vast 
  openness of the chasm. A scattering of glittering coins and 
  gems fills the intact section of the chamber. 
  Across a 20 foot gap, a broken bridge reaches out to the 
  far wall of the rift.
  
  56
  Gargantuan Gelatinous Cube
  Gargantuan ooze, unaligned
  Armor Class 6
  Hit Points 200 (16d10+128)
  Speed 20 ft.
  STR
  DEX
  CON
  INT
  WIS
  CHA
  20 (+5)
  3 (-4)
  28 (+8)
  1 (-5)
  6 (-2)
  1 (-5)
  Condition Immunities blinded, charmed, deafened, 
  exhaustion, frightened, prone
  Senses blindsight 120 ft. (blind beyond this radius), passive 
  Perception 8
  Languages -
  Challenge 9 (35,000 XP)
  Amorphous. The cube can move through a space as narrow as 
  1 foot wide without squeezing. 
  Ooze Cube. The cube takes up its entire space (10’x10’x20). 
  Other creatures can enter the cube’s space, but a creature that 
  does so is subject to the cube’s Engulf and has disadvantage 
  on the saving throw. 
  Creatures inside the cube can be seen but have total cover.
  A creature within 5 feet of the cube can take an action to 
  pull a creature or object out of the cube. Doing so requires a 
  successful DC 16 Strength Check, and the creature making the 
  attempt takes 20 (6d6) acid damage.
  The cube can hold 2 large creatures, 4 large creatures or up 
  to 16 medium or smaller creatures inside it at a time. 
  Transparent. Even when the cube is in plain sight, it takes a 
  successful DC 15 Wisdom (Perception) check to spot a cube 
  that has neither moved nor attacked. A creature that tries to 
  enter the cube’s space while unaware of the cube is surprised 
  by the cube. 
  Actions
  Multiattack. The cube makes 2 pseudopod attacks and an 
  Engulf action.
  Pseudopod. Melee Weapon Attack: +9 to hit, reach 10 ft, one 
  target. Hit: 21 (6d6) acid damage, and the target is grappled 
  (escape DC 16) and restrained until the grapple ends. At the 
  beginning of its turn a grappled creature takes 21 (6d6) acid 
  damage.
  Engulf. The cube moves up to its speed. While doing so, it can 
  enter the Huge or smaller creature’s space, the creature must 
  make a DC 16 Dexterity saving throw.
  On a successful save, the creature can choose to be pushed 
  5 feet back or to the side of the cube. A creature that chooses 
  not to be pushed back suffers the consequences of a failed 
  saving throw.
  On a failed save, the cube enters the creature’s space, and 
  the creature takes 21 (6d6) acid damage and is engulfed. The 
  engulfed creature can’t breathe, is restrained, and takes 35 
  (10d6) acid damage at the start of each of the cube’s turns. 
  When the cube moves, the engulfed creature moves with it. 
  An engulfed creature can try to escape by taking an action 
  to make a DC 16 Strength check. On a success, the creature 
  escapes and enters a space of its choice within 5 feet of the 
  cube. 
  
  57
  Treasure Golem
  Large construct, unaligned
  Armor Class 18 (Dex, natural armor)
  Hit Points 178 (17d10+85)
  Speed 30 ft., Fly 30 ft.
  STR
  DEX
  CON
  INT
  WIS
  CHA
  22 (+6) 14 (+2) 20 (+5)
  3 (-4)
  11 (+0)
  1 (-5)
  Damage Immunities poison, psychic; bludgeoning, piercing 
  and slashing from non magical weapons that aren't 
  adamantine
  Condition Immunities blinded, charmed, exhaustion, 
  frightened, paralysed, petrified, poisoned, prone
  Senses darkvision 120 ft., passive Perception 10
  Languages understands Undercommon but can't speak
  Challenge 10 (5,900 XP)
  Hoard Bound. The golem is bound to its treasure. It cannot 
  be banished or otherwise moved from the plane its hoard ex-
  ists on, and it can unerringly track every single coin or object 
  taken from its hoard.
  Immutable Form. The golem is immune to any spell or effect 
  that would alter its form. 
  Magic Resistance. The mind flayer has advantage on saving 
  throws against spells and other magical effects.
  Magic Weapons. The golems weapon attacks are magical. 
  Actions
  Multiattack. The golem makes 2 slam attacks or two treasure 
  spray attacks.
  Slam. Melee Weapon Attack: +10 to hit, reach 5 ft., one target. 
  Hit: 19 (3d8+6) bludgeoning damage.
  Treasure Spray. Ranged Weapon Attack: +10 to hit, range 
  40/80, one target. Hit: 19 (3d8+6) bludgeoning damage.
  All that Glitters (Recharge 5-6). The golem can generate a 
  hypnotic pattern effect in a 30 foot cube centred on itself 
  (which it is immune). Any creature in the area that sees the 
  pattern must make a DC 16 Wisdom saving throw. On a 
  failed save, the creature becomes charmed for the duration, 
  becoming incapacitated and has a speed of 0. The effect lasts 
  for 1 minute.  A target can repeat the saving throw at the end 
  of each of its turns, ending the effect on a success. The effect 
  ends if the creature takes damage, or another creature spends 
  an action to shake the creature out of its stupor. 
  
  58
  Molthglor's Garden
  The adventure location is designed for 4-6 characters of 
  level 12 (Tier 3, APL 12).
  Adventure Background
  The hidden garden is home to a powerful Mind Flayer 
  Arcanist (MM p222) named Molthglor. Removed from 
  the hivemind of mind flayers deep within the Underdark, 
  Molthglor ventured above ground, entering the Realms 
  Above from the deep recesses of an abandoned mine in 
  Chult. There he discovered a portal glimmering in the 
  darkness of the mine, through which the mage could 
  see nothing but a dank, stone-bricked dungeon room. 
  Stepping through the portal to explore, Molthglor found 
  a place to call home. It was not long before he discovered 
  the area around the portal to be a side-chamber of the 
  fabled Undermountain, the deadly dungeon of the 
  mad mage Halaster Blackcloak located deep beneath 
  Waterdeep. Not wanting to upset Halaster and his 
  minions, Molthglor—an exile without a people—bowed 
  before Halaster, pledging his life, power, and devotion 
  to the mad mage’s will. Molthglor now watches over 
  the portal to Chult in this chamber for Halaster. Using 
  illusionary magic to masquerade the room as a lush, 
  enchanted garden, the mind flayer now preys on any 
  wayward adventurers that happen to wander into his 
  domain, whether from within Undermountain or through 
  the portal from Chult.
  Adventure Hooks
  Discovery by Chance….
  The adventurers may simply stumble onto the shrine as 
  part of their travels within the halls of Undermountain.
  Sanctuary Rumors
  Rumors circulate within Skullport of a sanctuary for 
  weary adventurers somewhere in the dungeon. It is a 
  garden hidden behind a carved wooden door, protected 
  by a Unicorn.
  Travellers from Chult
  Traveling in the lands of Chult, the party come across a 
  hidden portal, either within a small cave hidden beneath 
  the jungle ferns, or deep within one of the abandoned 
  mines of Chult. The portal leads into the portal chamber 
  of Molthglor's Garden
  Molthglor's Garden
  1. Entrance from Undermountain 
  When the heroes enter through this door from the 
  winding passages of Undermountain, read or paraphrase 
  the following:
  At this point, the mind flayer is hiding in the chamber 
  on the eastern wall overlooking the garden. 
  General Features
  Ceilings. The ceiling in the main chamber is 50 feet high. 
  In the peripheral chambers, the ceiling is 12 feet in height. 
  Corridors have a ceiling height of 10 feet.
  Terrain Illusion. The garden terrain in this chamber is 
  an illusion powered by Molthglor’s casting of hallucinatory 
  terrain. He refreshes the spell each day. 
  The garden appears absolutely real. Any creature who 
  attempts to interact with the bushes, tree, or grass is no 
  longer under the effect of the illusion. A successful DC 15 
  Intelligence (Investigation) check also reveals the illusion 
  for what it is. 
  Upon any character’s disbelief of the illusion, five su-
  monsters (Tomb of Annihilation p232) immediately try to 
  surprise the characters, having hidden beneath the illusion. 
  Molthglor joins the combat attacking with spells from his 
  balcony when the illusion is broken. 
  Illusionary Curtain of Vines. Vines appear to grow 
  along and hang from high on the northern wall of the main 
  chamber. A successful DC 20 Wisdom (Perception) check 
  notices that these hang to conceal a room beyond. On a roll of 
  23 or higher, the hero also notices a shadowy figure looming 
  behind the curtain of vines. This is the mind flayer mage, 
  Molthglor, working his magic.
  Terrain Reality. Once the illusion is removed, the main 
  chamber is a large, grimy, and empty place. It is a square 
  dungeon chamber with two exits at ground level (the door 
  on the western wall leading into Undermountain, and a cave 
  entrance on the southern wall), and Molthglor’s balcony high 
  on the eastern wall. Rather than the illusionary giant apple 
  tree, a large, slime-covered stone pillar stretches from the 
  stone floor to the 50-foot high ceiling in the center of the 
  main chamber.
  As you look upon the room ahead, you see a sight you 
  didn’t expect in such a place as this. Green grass sprouts 
  from the floor. Beautiful bushes of raindrop shaped leaves 
  fill the area, and stand tall and strong around a large apple 
  tree the center of the area. The tree has grown so high that 
  it threatens to touch the 50-foot-high ceiling. The aroma of 
  pollen, flowers, and the peacefulness of nature in springtime 
  nourishes your senses. An overgrown forest track leads 
  around each side of the giant apple tree, leading towards a 
  heavenly glow at the opposite side of the beautiful garden.
  
  59
  
  60
   
  Stealthy Su-Monsters. Hiding behind the hallucinatory 
  terrain are 5 su-monsters (Tomb of Annihilation p232) 
  with a Dexterity (Stealth) roll of 20 against the opposed 
  passive Wisdom (Perception) of the characters. They 
  sit and wait for the characters to delve deeper into the 
  “garden” until they attempt to surprise them.
  Before any character can interact with the illusionary 
  terrain, read or paraphrase the following:
  Area 2. Unicorn Mound
  As the characters move around the tree on the path, 
  they see a beautiful and rare sight. Sitting atop a mound 
  of grass rests a unicorn, bold and beautiful in its radiant 
  power. She introduces herself as Heshna, and asks the 
  party to tell her of their journey thus far. She offers a 
  drink from a small pond of fresh water.
  Allow the party to converse with Heshna for as long 
  as the roleplay needs. Should a party member look 
  more closely at her, a successful DC 15 Intelligence 
  (Investigation) check realizes that Heshna is an illusion. 
  The unicorn was conjured via the major image spell cast 
  by Molthglor, for which he maintains concentration. 
  Once revealed as an illusion, the mind flayer releases 
  concentration and attacks the party.
  Water. The water is indeed water, but 
  the freshness of it is illusionary, and 
  a DC 15 Wisdom (Perception) 
  check sees past the illusion 
  to notice the water is in fact 
  stagnant 
  and 
  green. 
  Any 
  character who drinks this water 
  must succeed on a DC 15 Constitution 
  saving throw, becoming poisoned on 
  a failed save. If this happens, the illusion is dispelled, 
  revealing the water’s true form.
  Su-Monsters, Attack! Once the party has either seen 
  through the illusions, or rests comfortably unaware, 
  the five su-monsters attack, attempting to surprise the 
  party. Molthglor also joins the combat in the first round, 
  attacking with spells at range from his balcony. See 
  Stealthy Su-Monsters in Area 1.
  Area 3. Stairwell
  The entrance to this stairwell is hidden behind 
  Molthglor’s hallucinatory terrain, and looks like the rest 
  of the stone walls of the chamber. Once the spell has been 
  dismissed, or a character has seen through the 
  spell’s effects, the entryway to this stairwell 
  is clearly visible. To find the stairwell while 
  under the effects of the illusion, a character 
  must succeed on a DC 15 Wisdom 
  (Perception) check, at which point 
  feeling along the walls finds the hollow 
  beneath the illusion.
  Area 
  4. 
  Molthglor’s 
  Chamber
  This is the bedding chamber and 
  study for the mind flayer mage. In the 
  south-west corner is a large study desk 
  carved of black marble with deep purple 
  veins running through it. An open 
  spellbook sits on its surface. A large 
  You hear an angelic voice float over the serene garden 
  from the radiant glow on the opposite side of the giant 
  apple tree, it says, “Welcome to my home. You can be 
  sure this is a place of peace—a place where those of you 
  with good natures are invited to rejuvenate your weary 
  and battered bodies. I have but one request: please do not 
  touch my lovely garden else my fury will be unstoppable. 
  So please stay to the path, follow it and join me in my 
  sanctuary, as it is yours to share.”
  
  61
  wooden bed with black silk sheets is situated along the 
  northern wall. 
  A balcony overlooks the illusionary garden. Every inch 
  of the chamber can be seen from this viewpoint, apart 
  from the area behind the giant apple tree/pillar. A large 
  chest is against the eastern wall.
  The Chest. This chest is unlocked, however Molthglor 
  has inscribed a glyph of warding spell within the inside 
  of the chest’s lid. If the chest is opened, glyph breaks and 
  triggers explosive runes which erupt with lightning in a 
  20-foot-radius sphere centered on the chest. Any creature 
  caught in the area when the trap is triggered must make 
  on a DC 20 Dexterity saving throw, taking 5d8 lightning 
  damage on a failed save, and half as much damage on a 
  successful one.
  Safely Opening the Chest. To open the chest safely, 
  a DC 15 Intelligence (Investigation) check reveals that 
  the back of the chest has a hidden drawer which can 
  be easily slid out giving access to the chest’s treasure 
  without triggering the glyph. Looking inside the chest 
  from this angle also notices the glyph of warding that 
  remains unbroken and stable until the lid is opened.
  Treasure. The spellbook on top of the marble desk is 
  Molthglor’s, and contains all of the spells listed on his stat 
  block. The treasure chest contains 3 gemstones - a tiger 
  eye (10 gp), a blue quartz (10 gp) and a bloodstone (50 
  gp). There is also a ring of mind shielding (DMG p191).
  Area 5. Portal to Chult
  This is a permanent portal which acts as a 
  dimensional gateway between this chamber 
  and one of the many unnamed mines on Chult 
  (your discretion). This room can act as a conduit 
  between the Tomb of Annihilation and Dungeon of 
  the Mad Mage hardcover adventure books.
  Su-Monster
  Medium monstrosity, chaotic evil
  Armor Class 12
  Hit Points 27 (5d8+5)
  Speed 30 ft., Climb 30 ft.
  STR
  DEX
  CON
  INT
  WIS
  CHA
  14 (+2) 15 (+2) 12 (+1)
  9 (-1)
  13 (+1)
  9 (-1)
  Skills Athletics +6, Perception +3 
  Senses passive Perception 13
  Languages -
  Challenge 1 (200 XP)
  Actions
  Multiattack. The su-monster makes two attacks: one with its 
  bite and one with its claws..
  Bite. Melee Weapon Attack: +4 to hit, reach 5 ft., one target. 
  Hit: 4 (1d4+2) piercing damage.
  Claws. Melee Weapon Attack: +4 to hit, reach 5 ft., one target. 
  Hit: 7 (2d4+2) slashing damage., or 12 (4d4+2) slashing 
  damage if the su-monstyer is hanging by its tail and all four of 
  its limbs are free.
  Psychic Crush (Recharge 5-6). The su-monster targets one 
  creature it can see within 30 feet of it. The traget must succeed 
  on a DC 11 Wisdom saving throw or take 17 (5d6) psychic 
  damage or be stunned for 1 minute. The stunned target can 
  repeat the saving throw at the end of each of its turns, ending 
  the effect on itself on a success.
  
  62
  
  63
  Sargauth Sanctuary
  The adventure location is designed for 4-6 characters of 
  level 12 (Tier 3, APL 12).
  Adventure Background
  For a long time now, patient aboleths have watched 
  Halaster’s expansion of Undermountain with growing 
  interest. They have built outposts on various levels of the 
  dungeon in order to oversee the mad mage’s movements, 
  up to and including the city of Skullport.
  In the lawless and chaotic Port of Shadows, strange sights 
  and sudden disappearances are a daily occurrence. As 
  yet, the aboleth incursion has drawn little notice, which 
  serves the malevolent creatures well indeed.  
  Adventure Hooks
  Aboleth allies and slaves move about both within 
  Skullport and its surrounding areas. Here are a few ways 
  the party may arrive at the caves:
  Shy and Aleyne
  Aleyne (uh-layn) is part of a band of adventurers that 
  recently went missing near Skullport. He has a friend 
  named Shy within the city who has become desperately 
  concerned for him. The last Shy knew, Aleyne was 
  headed out to investigate the caves to the south-east of 
  Skull Island.
  Strange Sightings
  Aboleth slaves can sometimes be spotted within the city 
  wearing damp wrappings or soaked clothing to keep their 
  skin moist. Closer inspection reveals discolored skin and 
  odd mannerisms.
  Pursuit
  The party may stumble across the caves while attempting 
  to evade pursuit. The cave’s small entrance grants an 
  easy method of escape from larger sailing vessels.
  The Caves
  The aboleth lair lies within a cave system to the south-
  east of Skull Island, near Skullport. It is easy enough for 
  visitors to miss the entrance if they do not know what they 
  are looking for; the crevice blends into the surrounding 
  cave walls and quickly curves away, allowing no light to 
  enter or exit the main cavern.
  It is assumed that the party approaches in a small boat. 
  Adjust as appropriate if this is not the case: a large boat 
  does not fit into the entrance, but the party may choose to 
  fly or swim if they are able. Treat any vessel small enough 
  to enter as a rowboat as per page 119 of the Dungeon 
  Master’s Guide, except that it is large enough to carry 
  the entire party along with reasonable luggage. It can be 
  rowed at a rate of 20 ft per round, assuming 2 people are 
  rowing. If desired, allow a Strength (Athletics) check to 
  make the boat move at a faster pace; a result of at least 
  15 allows them to move at 30 feet per round, and a result 
  of at least 20 allows 40 feet of movement.
  1. Entrance
  The entrance is a narrow passageway with several 
  sharp curves and a vicious current. Have whoever is 
  rowing make a DC 16 Strength (Athletics) check, adding 
  General Features
  Sights. The aboleths have taken up residence in a natural 
  cave system. The ceiling and walls are rough, uneven stone, 
  smoothing slightly at the point where they meet the river. 
  The water is dark and slightly oily. The cave system is dark 
  except for the light sources specifically mentioned in the 
  text.
  Sounds. The motion of the river changes based on the 
  size and shape of each section of the caves: in some places 
  it is nearly still, while in others it bubbles along furiously. 
  The differing rhythms echo chaotically across the space, 
  confusing listening ears. In areas where the river quietens, 
  the silence is instead filled with the sounds of dripping 
  water and a strange hum so quiet it can barely be heard.
  Smells. The cave air is stagnant and salty. Hovering 
  beneath these scents is a fainter, less pleasant stench of oil 
  and decaying fish.
  Touch and Taste. The temperature is moderate, 
  including in the water, however the aboleth presence has 
  further befouled the salty water of River Sargauth (see 
  “Regional Effects” MM p14). Swimming through it feels 
  like swimming in slime, with an additional touch of horror 
  that goes beyond mere physical sensation. A creature can 
  swim in the affected water for a number of minutes equal 
  to its Constitution score before suffering any ill effects. For 
  every ten minutes after this, a creature that is not allied with 
  the aboleths must succeed on a DC 13 Constitution saving 
  throw or take 1d4 psychic damage.
  
  64
  
  65
  their proficiency if they have experience with boats and 
  granting advantage if at least one other character is 
  assisting. On a success, they navigate the boat without 
  incident. On a failure, it takes 4 (2d4) damage as it 
  scrapes against the cave walls. If the boat is reduced to 
  0 hit points, it breaks apart and anyone inside falls into 
  the water.
  Four of the boats hold five thugs (MM p350) each. The 
  remaining boat, placed near the center, holds four thugs 
  and a mage (MM p337). All of the boats have the stats of 
  a rowboat (DMG p119). 
  If the party have a light source of their own, they are 
  spotted as soon as they enter the cavern. If not, the party 
  can attempt a DC 15 group Dexterity (Stealth) check 
  to avoid detection until they are within 60 feet of another 
  boat. If at least one thug spots the party, they call out to 
  alert the others.
  The thugs were hired by Aleyne, an adventurer enslaved 
  by an aboleth. Aleyne paid a generous hire fee, along 
  with enough intimidation to earn the respect of the thugs 
  without also earning their resentment. The thugs have 
  two jobs: first, to scare off or fight any large groups 
  that come through; and secondly, to demand a toll 
  from any smaller groups. The mage, Illestra, 
  was also hired by Aleyne, though she is less 
  enthusiastic about her duty guarding this 
  wretched, dismal lake. She does her best 
  to blend in, and only involves herself if a 
  fight breaks out which involves one or more 
  spellcasters. Illestra is wearing a cloak of 
  the manta ray (DMG p159).
  If there are six or more characters in 
  the party, the thugs refuse to let them 
  pass without a fight. Otherwise, they 
  demand a “scavengers fee” of 500 gp, 
  which can be negotiated down to 200 gp with an 
  opposed Charisma (Persuasion) check against 
  the thugs’ Wisdom (Insight). The thugs do not know 
  what is beyond this chamber, though they have seen 
  various people enter. Most of those who enter either do 
  not return, or are changed on their return. They know 
  also that Aleyne is inside somewhere, but they haven’t 
  seen him in days. Aleyne wears a cloak and a scarf 
  around his face, both of which are constantly damp. This 
  may have something to do with Aleyne’s skin condition.
  Treasure. There is a total of 2,400 gp held on the boats, 
  along with various mundane items. Illestra’s component 
  pouch holds a pearl worth 100 gp and a diamond worth 
  500 gp. One of the thugs has a dagger of venom (DMG 
  p161).
  2. Rapids
  A kuo-toa (MM p199) waits inside the passageway. As 
  the party approaches, they see it survey the party and then 
  begin to swim further into the caves. This kuo-toa has 
  been enslaved by the aboleths and has little conscious 
  thought of its own remaining. It has been ordered to 
  lead the party into the caves, and it does not respond to 
  questioning.
  As the boat enters the rapids, it moves at a rate of 
  60 feet per round. The party must make a DC 17 
  group Strength (Athletics) check. On a failure, 
  the boat takes 2d6 damage, and all creatures in 
  it must immediately make a DC 12 Dexterity 
  saving throw or be knocked prone – any 
  who fail by more than 5 points are tossed 
  from the boat. If the boat breaks apart, 
  all passengers are flung into the water. 
  A creature thrown from the boat takes 
  14 (4d6) bludgeoning damage as 
  they are flung through the rapids and 
  against the rocks.
  The rapids continue for 200 feet. Half 
  way down, characters looking ahead spot 
  that the rapids end in a sudden drop. They 
  have two rounds to act: ask for a snap decision 
  With one last abrupt turn, the crevice opens to a broad 
  chamber filled with dark water. Five points of light mark 
  the presence of boats floating on the surface of the 
  subterranean lake: three at the center of the cavern and two 
  further to the right, where another passageway continues 
  into the darkness.
  Progress is slow to begin, but your vessel soon picks 
  up speed. The noise of the river grows louder and louder 
  until you round a bend and peer down at a steep slope of 
  churning rapids stretching down before you.
  
  66
  as there is no time to strategize. The following events 
  occur unless heroes act to avoid them:
  1. The boat continues on past the edge, slams into 
  the opposite wall and is destroyed, dealing 7 (2d6) 
  bludgeoning damage to anyone inside.
  2. All characters, starting with any that were inside the 
  boat, fall 20 feet and land in deep water.
  If it was not stopped earlier, the heroes spot the kuo-
  toa from Area 3, swimming towards Area 4. The party 
  see it turn towards the right. It is gone by the time they 
  approach.
  3. Mushroom Grove
  50 aboleth slaves are scattered throughout the cavern. 
  Most are kuo-toa, but there are a few other humanoids 
  from Skullport and its surrounds. You can add your own 
  NPCs to this group if it makes sense for your table’s 
  story arc. All aboleth slaves in this area are tranquil and 
  resigned. They react slowly and show no alarm, even if 
  shaken or threatened. If a character speaks to them in 
  a language they understand, they respond by inviting 
  the party to lie down and enjoy their surroundings. If a 
  slave is attacked and not killed in a single blow, they can 
  make a DC 14 Wisdom saving throw: on a success, the 
  aboleth’s enslavement ends. Humanoid slaves awakened 
  in this way are confused and distressed, while the kuo-toa 
  slaves fly into a rage and attack, screeching, “You stole us 
  from the blessed one!”
  If the aboleths require healing, they draw from these 
  slaves using their Psychic Drain. Freeing or killing the 
  slaves prevents the aboleths from using this ability. If the 
  party are aware that they face aboleths, a successful DC 
  20 Intelligence (History) check reveals this information.
  Water Level. The water is shallower in this area, 
  especially towards the edges of the cavern and pathways 
  to Areas 4 and 5, where it is shallow enough to wade. In 
  addition to these caverns, a few smaller tunnels carry the 
  water deeper into Undermountain.
  Treasure. Some of the slaves carry valuable items, 
  and in addition, some of their material possessions are 
  scattered around the room. If the party take time to 
  search, they find the following: 543 gp, 123 sp, a ring 
  of water walking (DMG p193), a cap of water breathing 
  (DMG p157), an oathbow (DMG p183) and 3 potions of 
  healing (DMG p187).
  The mouth of another cave opens before you, dotted with 
  faint points of sickly green light.
  A forest of gigantic mushrooms rise from the murky 
  water, faintly lit by glimmering phosphorescent lichen. In 
  between the immense stalks you spot tens of small, pale 
  humanoids, floating serenely in the filthy water.
  
  67
  4. Meeting Chamber
  The figure is an illusory copy, not the aboleth itself. 
  See Regional Effects (MM p14) for details. It has been 
  alerted to the party’s presence through its kuo-toa spy and 
  through all other the eyes in Area 3. If desired, allow the 
  heroes to make DC 17 Intelligence (History) checks to 
  see what they know about aboleths; the higher the result, 
  the more they recall. Use the background information and 
  statistics in the Monster Manual.
  The aboleth speaks slowly and with leisure. It has lived 
  for eons, with the memories of countless lives before it, 
  and it holds no sense of urgency. If the party communicate 
  with the aboleth, use the following points to respond: 
  • 
  Who are you? The aboleth’s name is a jumble of 
  telepathic images. It is amused, rather than offended, 
  if the party provide a nickname for it.
  • 
  What is this place? “My companions and I reside in 
  this place, as scouts for others of our kind. We have 
  become curious about this mage, Halaster, and his 
  kingdom. We desire to learn more.”
  • 
  Where is Aleyne? “Right beside me. Do you see him?” 
  The aboleth shifts, and the party can see the figure of 
  Aleyne. “Those who resist rarely resist for long. Yet I 
  can offer much if you will serve willingly.”
  The aboleth soon moves the conversation back to its 
  own objectives: discovery of new information and the 
  capture of new slaves. Through its telepathic probing, it 
  has learned the desires of the party, and can begin to offer 
  its assistance. Roleplay the interaction accordingly. The 
  aboleth is not exactly charming, but its words are well-
  chosen.
  Aleyne is also capable of responding to questioning, 
  though he speaks minimally and with little emotion. See 
  “Background” below, or the following points:
  • 
  What are you doing here? “My companions and I 
  came here to investigate the caves.”
  As you glance into the cavern, you see something move: a 
  gigantic, mottled green creature rises from the water. Its form 
  is utterly alien—slimy and misshapen with rows of sharp teeth 
  filling an oversized jaw.
  A strange, sibilant voice sounds not in your ears but in your 
  mind. Glancing over to your companions, you can tell that they 
  hear it as well.
  “Welcome, friends. You have travelled far, I see. What is it 
  that you seek?”
  
  68
  • 
  Where are your companions? “Dead. I killed them 
  all.”
  • 
  Why did you do that? “I don’t know.”
  • 
  Shy is waiting for you. Aleyne does not respond.
  If the aboleth is either attacked or is unable to convince 
  the party into an alliance, it disappears and sends Aleyne 
  to attack. See below for Aleyne’s stats.
  Background. Aleyne was once part of an adventuring 
  party that set out to investigate the caves. He and his 
  companions fell afoul of the aboleths, and while the 
  others fought, Aleyne was caught by the aboleths’ 
  magical enslavement and was forced to fight his own 
  companions. He is firmly within their control now and 
  has disadvantage on any saving throws to end the effect; 
  what remains of his true personality is stricken with grief, 
  guilt and madness, and he welcomes the loss of control 
  that the aboleths offer him. He does however remember 
  Shy (see Adventure Hooks): if she is with the party, or if 
  they manage to capture and take him back to Skullport, 
  he has advantage on these checks in her presence.
  Tactics. Aleyne is a spellcaster and prefers to avoid 
  melee range. He uses misty step to find a strategic 
  position atop a mushroom in Area 3, and then casts at the 
  party from a distance. He also has a necklace of fireballs 
  (DMG p182) with 3 beads.
  Development. As the fight continues, 4 chuuls (MM 
  pg. 40) approach from Area 5 and attack the party.
  Treasure. Aleyne has a +1 rapier along with 342 gp, 
  221 sp and 53 cp (and however many beads remain on 
  his necklace of fireballs).
  5. Final Threshold
  There is nothing of value within the cave itself. It merely 
  holds a passageway to Area 6, where the aboleths reside. 
  Thanks to the many eyes scattered around Area 3, those 
  aboleths are immediately alerted if the party attempt to 
  enter the passageway to their lair. If they have not yet 
  met the illusory aboleth from Area 4, it manifests behind 
  them and calls out telepathically. If this interaction has 
  already occurred, then there is no further reaction.
  Area 6 is only accessible to those able to breathe 
  underwater, either naturally or through magical means. 
  The water is tainted by the aboleth presence (see 
  Introduction), and this sensation grows worse as they 
  enter the cave, indicating that the aboleth lair lies beyond. 
  The party may still turn back if they wish.
  The passageway continues for many minutes. Towards 
  the bottom, luminescent grasses wave on the seafloor 
  and the way begins to curve upwards again until the party 
  arrive in Area 6.
  6. Aboleth Lair
  The area holds the ruins of an ancient, fallen aboleth 
  dwelling, now connected to Undermountain via River 
  Sargauth.
  By the time the party have made it to this place, the 
  aboleths are well aware of their presence. If the party 
  approach with weapons drawn, the aboleths and their 
  minions attempt to utterly crush the party. This is a deadly 
  encounter unlikely to end well for characters below level 
  17.
  Creatures. There are 2 aboleths (MM p13) and 20 
  chuuls (MM p40).
  Tactics. The aboleths first target any spellcasters with 
  their Enslave ability, then use their tentacles to deal 
  with melee fighters and their Psychic Drain to heal any 
  damage. If the damage becomes overwhelming, they hide 
  behind the chuuls to heal themselves. They are not afraid 
  of death (as they regenerate on the Elemental Plane of 
  Water) but still flee if the situation becomes dire; it is 
  inconvenient to lose their current position.
  The cave is empty and unremarkable, save for a slight 
  glow from below: you can see tiny, luminescent creatures 
  floating in the water, beckoning the way to the depths.
  The natural cave walls give way to a structure that seems 
  purely artificial, yet clearly untouched by humanoid hands. 
  A broad circular chamber rises before you, built of some 
  unknown pale material that glimmers with arcane light. 
  Even as you pause to marvel at the construction, the shape 
  of an aboleth rears up before you.
  
  69
  Aleyne
  Medium humanoid (teifling), chaotic neutral
  Armor Class 13 (16 with mage armor)
  Hit Points 104 (16d8+32)
  Speed 30 ft.
  STR
  DEX
  CON
  INT
  WIS
  CHA
  13 (+1) 16 (+3) 14 (+2) 18 (+4) 11 (+0) 17 (+3)
  Saving Throws Int +8, Wis +4
  Skills Acrobatics +7, Arcana +8, History +8, Perception +4, 
  Persuasion +7
  Damage Resistances fire
  Senses darkvision 60 ft., passive Perception 14
  Languages Common, Draconic, Infernal, Undercommon
  Challenge 11 (7,200 XP)
  Innate Spellcasting. Aleyne's spellcasting ability is Charisma.
  He can innately cast the following spells, requiring no material 
  components:
  At will: thaumaturgy
  1/day each: hellish rebuke, darkness
  Magic Resistance. Aleyne has advantage on saving throws 
  against spells and other magical effects.
  Spellcasting. Aleyne is a 16th level spellcaster. His spellcast-
  ing ability is Intelligence (spell save DC 16, +8 to hit with spell 
  attacks). He has the following wizard spells prepared:
  Cantrips (at will): fire bolt, light, mage hand, message, prestidigi-
  tation
  1st level (4 slots): detect magic, mage armor*, magic missile, 
  shield
  2nd level (3 slots): alter self, crown of madness, mirror image, 
  misty step
  3rd level (3 slots): counterspell, fly, lightning bolt
  4th level (3 slots): banishment, dimension door
  5th level (2 slots): cone of cold, dominate person
  6th level (1 slot): chain lightning, globe of invulnerability
  7th level (1 slot): finger of death, teleport
  8th level (1 slot): mindblank*
  *Aleyne casts these spells on himself before combat.
  Actions
  Rapier. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. 
  Hit: 7 (1d8 + 3) piercing damage.
  Development. Successfully casting banishment on an 
  aboleth ends the charm effect on any number of affected 
  creatures. If desired, any key NPCs you chose to include 
  in this group may then decide to assist the party. The 
  aboleths cannot use their Psychic Drain on creatures 
  who are not charmed.
  Treasure. The hall holds various ancient relics. Their 
  true historical value is immeasurable, but even a fragment 
  of the aboleth structure can sell for up to 5,000 gp if the 
  right buyer is found.
  
  70
  Cathedral of Bones
  The adventure location is designed for 4-6 characters of 
  level 13 (Tier 3, APL 13).
  Adventure Background
  Varenius Helthon, also called The Black Baron, is 
  a skull lord created by and devoted to the dead god 
  Myrkul. The three souls that make up Varenius were all 
  powerful followers of the Lord of Bones and each vied to 
  become the god’s herald. Myrkul was pleased with their 
  eagerness, so he killed them all and bound their souls 
  together, giving the creature a new name, Varenius. The 
  Lord of the Dead cast Varenius into the Shadowfell, 
  where he was ordered to forge his own domain and 
  spread reverence to Myrkul.
  After Myrkul’s defeat at the hands of Mystra and 
  Elminster atop Blackstaff Tower, Varenius vowed to find 
  a way to return his lord to unlife. He came to Waterdeep, 
  where he entreated with Halaster, knowing the Mad 
  Mage is one of Toril’s most powerful mages. Now, he 
  supplies Halaster with undead minions to protect the 
  halls of Undermountain. Varenius believes that allying 
  with Halaster will provide him secret knowledge into 
  how Myrkul died and a chance to strike at his dead lord’s 
  enemies.
  Adventure Overview
  The characters discover a section of Undermountain 
  controlled by a powerful skull lord. He has 
  converted the area into  profane temple 
  to Myrkul. While exploring the area, the 
  characters will learn more about the 
  murderous cult of Myrkul and confront 
  one of Undermountain’s most powerful 
  necromancers.
  Adventure Hooks
  The Shadows Have Claws
  While recovering in The Yawning Portal 
  or another Waterdhavian tavern, the 
  characters overhear a group of young 
  adventurers recounting their recent 
  foray into Undermountain. They were 
  assaulted from the shadows by an 
  undead monstrosity with claws as large 
  as trolls. The party can lead the characters to where they 
  believe the monster lairs: behind a door of bones.
  Artisan’s Brand
  After battling a group of undead in the halls of 
  Undermountain, the characters discover that each 
  creature is branded with the same symbol: three 
  conjoined humanoid skulls, the middle one wearing a 
  jeweled crown.
  The Cathedral
  1. The Door of the Dead
  As the characters approach, read or 
  summarize:
  General Features
  Sights, Sounds, and Smells. Tattered tapestries depicting 
  Myrkul commanding undead hang from the walls. Black mold 
  grows across the damp floor and walls.
  There is a constant splatter of water against stone coming 
  from below. In quiet moments the characters hear the soulless 
  groan from a distant zombie.
  The area smells of death and decay.
  Doors and Walls. Unless noted otherwise, all doors are 
  made from iron-reinforced wood (AC 16, 20 hit points). Doors 
  are unlocked unless noted otherwise.
   Unless noted otherwise, all walls are made from 5-foot 
  thick smooth stone masonry (AC 17, 50 hit points per 5-foot 
  cube) and are 10 feet tall. 
  Lighting. Unless noted otherwise, the dungeon is dimly lit 
  by candles ensconced in the walls.
  Standing alone at the end of 
  the hall is an imposing bone door, 
  a black gem the size of an ogre’s 
  hand set in the center. Upon closer 
  inspection you realize the bones 
  are not a door but a barricade; a 
  monument to death eternal. Piles 
  of polished skulls flank each side 
  of the barricade. Skulls impaled on 
  iron spikes glow with a dying green 
  flame. The scene is a macabre 
  painting.
  
  71
  Each bone in the barricade is etched in Abyssal, 
  detailing how that individual met a violent end. The large 
  onyx gem is Varenius’ apprentice’s failed phylactery (see 
  Area 4 for more information). A detect good and evil spell 
  or a paladin’s Divine Sense feature reveal the gem is 
  desecrated. The gem emits a magic aura of necromancy. 
  Characters with a passive Arcana of 13 or higher know 
  that onyx is used in necromancy spells.
  The door can only be opened by undead creatures. 
  Any living creature who touches the barricade takes 
  11 (2d10) necrotic damage and must succeed a DC 16 
  Constitution saving throw or have its hit point maximum 
  decreased by an amount equal to the damage taken. This 
  reduction lasts until the target finishes a long rest. The 
  creature dies if this effect reduces its hit point maximum 
  to 0. If this effect kills a creature, increase the damage of 
  this effect by 1d10 for the next 24 hours for each creature 
  slain.
  If dispel magic is cast on the door (functions as a 5th-
  level spell), the magic is disabled for 1 hour and living 
  creatures can open the door without ill effect during 
  that time. If the gem is removed with either a successful 
  DC 18 Dexterity check using thieves’ tools or a DC 18 
  Strength check, the magic ends and the bones fall to the 
  ground, revealing Area 2.
  Creatures. The torches are actually 4 flameskulls 
  (MM p134). They remain docile until a character touches 
  or tampers with the door. Characters with a passive 
  Perception of 13 or higher are not surprised when they 
  
  72
  attack. The flameskulls shout prayers to Myrkul as they 
  attack. They pursue the characters up to 200 feet away 
  from the door before returning to their post.
  Treasure. The large onyx gemstone is worth 600 gp 
  and weighs 35 pounds.
  Developments. If there is combat near the door, 
  Varenius, in Area 2, prepares by casting mirror image 
  and then readying cloudkill.
  2. The Dread Sanctuary
  As the characters enter, read or summarize:
  Varenius’ captain, a vampiric cleric who resides in 
  the Shadowfell, desecrated this area with a hallow spell 
  (spell save DC 16), using the Fear extra effect.
  If a character inspects the tapestries and succeeds a 
  DC 13 Intelligence (Investigation) check, they surmise 
  that the skull lord once had an apprentice, which he then 
  killed.
  Creatures. Varenius Helthon, a skull lord (MToF 
  p230), is in the sanctuary praying to Myrkul. He attacks 
  the characters on sight, pledging to turn their flesh into a 
  monstrous creation. 
  Tactics. Varenius may have prepared actions (see 
  Developments, above). He attacks using spells, reserving 
  finger of death until an enemy is nearly dead.
  The skull lord uses his Legendary Resistance to save 
  against spells that would prevent or hinder him from 
  casting spells, such as feeblemind and slow.
  Adjusting this Encounter
  Here are some suggestions for adjusting this  
  encounter, according to your group. These are not 
  cumulative.
  • 
  Very Weak: Remove 1 Flameskull
  • 
  Weak: Reduce the flameskulls’ hit points by 10 each.
  • 
  Strong:Increase the flameskulls’ hit points by 10 
  each
  • 
  Very Strong: Add 1 flameskull and increase the 
  flameskulls’ hit points by 10 each
  A bone chandelier hangs from the ceiling of this dark 
  sanctuary, the skulls thick with dried candle wax. Pews of 
  knotted ebony adorned with fanged skulls stand as silent 
  sentries along the nave. A dozen intact humanoid skeletons 
  dressed in dark robes hang from the walls holding weapons, 
  unholy symbols, and magical implements. Between each 
  skeleton are worn tapestries depicting the conquests of a 
  three-skulled skeleton. 
  The same three-skulled creature looms over a small altar 
  draped in black linen. The three skulls twist unnaturally to 
  peer at you. One cackles while the central skull smiles with 
  a cold malignancy.
  
  73
  Varenius uses Legendary Actions to summon 5 
  skeletons (MM p272). If he has 3 or more skeletons, he 
  casts cantrips with Legendary Actions.
  Varenius fights until brought to 60 or fewer hit points. 
  Then he casts dimension door, teleporting to Area 5.
  Treasure. Displayed on the altar are spells scrolls of 
  animate dead and enervation (XGtE 155), written on 
  flayed skin. There is also a curved bone dagger set with 
  onyx and rubies worth 400 gp.
  If the characters search the room with detect magic or a 
  similar effect, they notice that one of the skeletons affixed 
  to the wall holds a magic wand. It is a cursed wand of 
  fear. See below for more information on the wand and 
  its curse.
  See Area 5 for Varenius’ treasure.
  Developments. If Varenius successfully retreats to 
  Area 5, he drinks a necromantic potion, regaining 8d4 
  + 8 hit points. He orders his servant, a wraith (MM 302), 
  to harass the intruders. The wraith uses hit-and-run 
  tactics, making use of its Incorporeal Movement trait to 
  retreat through walls, instead of engaging the characters 
  outright. If brought to 30 or fewer hit points, the wraith 
  retreats back to Area 5.
  3. Cleaning Cells
  As the characters enter, read or summarize:
  These cells are used to prepare dead humanoids taken 
  from Undermountain’s halls for reanimation. Each body 
  has its wounds stitched and crudely cared for to make a 
  more perfect undead. Some corpses are flayed, their skin 
  used for other creatures while the skeleton is reanimated.
  The cell doors are locked. If a character succeeds a DC 
  14 Dexterity check using thieves’ tools to pick the lock 
  or DC 20 Strength check to force the door open, they 
  can enter the cells. Forcing a door open creates enough 
  noise to alert the zombies as well as the guards in Area 
  3A. Each door has AC 19 and 20 hit points.
  Creatures. A zombie (MM p316) is in each cell, 
  preparing a body for reanimation. The zombies cannot 
  open the cell doors from inside. If the characters succeed 
  on a DC 8 Dexterity (Stealth) check, they can move 
  down the hall without being noticed. If the characters 
  fail or do not use Stealth, the zombies stop working to 
  grapple and attack the characters from between the bars. 
  Both the zombies and the characters have half cover (+2 
  to AC and Dexterity saving throws) due to the doors.
  Developments. If the zombies notice the characters, 
  they make enough noise to alert the guards in Area 3A. 
  The vampire spawn climb onto the ceiling and Hide from 
  the characters, preparing to ambush the characters when 
  they enter. If the characters do not enter within 2 minutes 
  of the zombies attacking, the vampire spawn move into 
  the hallway to attack.
  If the characters make it to the door to Area 3A 
  without being noticed and succeed on a DC 14 Wisdom 
  (Perception) check, they overhear creatures talking 
  about needing to “unleash the apprentice for more 
  bodies.”
  3A. Guard Room
  This small room is used to oversee the zombies’ and 
  respond to any reanimation subjects who may not be 
  quite dead yet.
  Creatures. Two vampire spawn (MM p298), created 
  by Varenius’ captain, are in this room. They attack the 
  characters on sight and pursue them throughout the 
  dungeon.
  A long hallway stretches out before you with five barred 
  cells on either side. A sickening wet thud like a meat 
  cleaver hacking through mutton pierces the silence. An 
  acrid smell burns your senses.
  Adjusting this Encounter
  Here are some suggestions for adjusting this  
  encounter, according to your group. These are not 
  cumulative.
  • 
  Very Weak: Reduce Varenius’ hit points by 20 and 
  decrease the hallow effect to DC 14.
  • 
  Weak: Reduce Varenius’ hit points by 20.
  • 
  Strong: Increase Varenius’ hit points by 30.
  • 
  Very Strong: Increase Varenius’ hit points by 30 
  and increase the hallow effect to DC 17.
  
  74
  Treasure. Several ledgers written in Abyssal detailing 
  how many bodies have been processed lie open on 
  the table. Some have a note that says “gathered by the 
  apprentice.”
  If the characters succeed a DC 15 Intelligence 
  (Investigation) check while searching the room, they 
  discover a false bottom in a desk drawer. Inside are 
  several potions: potion of hill giant’s strength, potion of 
  gaseous form, and a potion of mind reading.
  4. The Loathsome Apprentice
  As the characters enter, read or summarize:
  The door to this area is locked, requiring a 
  successful DC 16 Dexterity check using thieves’ 
  tools to unlock or DC 18 Strength check to force 
  open. If the characters force the door, the creatures 
  below Hide and prepare an ambush.
  The 10-foot-wide iron staircase spirals downward 
  for 40 feet, leading to a drainage collection chamber. 
  Water flows into this area from other locations within 
  Undermountain, eventually draining out of the dungeon. 
  The water collection chamber is filled with a foot of 
  stagnant water, creating difficult terrain for any creature 
  without a swim speed. The four alcoves are steeply sloped 
  and filled with 15 feet of water. Unless a character has 
  a swim speed, they must succeed on a DC 10 Strength 
  (Athletics) check to stay above water while in an alcove.
  The stairs are slick with blood and gore from the 
  recently slain elf. Unless the characters move at half 
  speed along the stairs, they must succeed on a DC 10 
  Dexterity saving throw or fall down the stairs, taking 
  14 (4d6) bludgeoning damage from the fall and landing 
  prone.
  Creatures. Varenius’ apprentice, now a boneclaw 
  (MToF p121), and 5 shadows (MM p269) are in the water 
  collection chamber. If they are alerted to the characters’ 
  presence, they Hide and prepare an ambush.
  The boneclaw was once Varenius’ apprentice, a powerful 
  necromancer herself. She was close to completing the 
  dark ritual required to become a lich, but Varenius, 
  fearing she may overpower him in undeath, wove a 
  powerful curse over her soul, weakening it just before 
  transferring it to a phylactery – 
  the onyx gem in Area 1. 
  The ritual failed and 
  the apprentice died, 
  but returned as 
  a 
  boneclaw 
  bound 
  to 
  Varenius. 
  Varenius 
  despises 
  Adjusting this Encounter
  Here are some suggestions for adjusting this  
  encounter, according to your group. These are not 
  cumulative.
  • 
  Very Weak: Remove 1 zombie and reduce the 
  vampire spawns’ hit points by 20 each. 
  • 
  Weak: Reduce the vampire spawn’s hit points by 
  15 each
  • 
  Strong: Increase the vampire spawns’ hit points by 
  20 each.
  • 
  Very Strong: Add 1 vampire spawn and increase 
  the vampire spawns’ hit points by 20 each.
  As you push the door open, the smell of old blood 
  assaults your nose, leaving a sickly metallic taste in the 
  back of your throat. A few steps down from the entrance 
  you see a dismembered elf, his face twisted in a horrific 
  death mask. The body ends at the waist, the legs accounted 
  for in the blood and gore that covers the stairwell. The 
  chamber below sounds almost peaceful as water steadily 
  flows into a pool.
  
  75
  the creature, but understands its usefulness. The three 
  souls within Varenius bicker over what to do with 
  the monster. For now, Varenius feeds it troublesome 
  adventurers.
  Tactics. The boneclaw uses Shadow Stealth to 
  Hide, gaining advantage on attacks. After grappling an 
  opponent, it uses Shadow Jump, teleporting into an 
  alcove.
  The shadows attempt to draw the characters into 
  the boneclaw’s deadly reach. They swarm grappled 
  characters, sensing an easy target.
  Treasure. If the characters search the alcoves and 
  succeed on a DC 13 Wisdom (Perception) check, 
  they find a dead adventurer carrying a longbow +1, 20 
  arrows +1, a potion of greater healing, and a coin purse 
  containing 20 pp and 12 gp.
  Developments. A character might recall the tapestries 
  in Area 2 depicting the apprentice’s death. At your 
  discretion, you can remind them of this information if they 
  succeed on a DC 12 Intelligence check. Alternatively, 
  if the characters succeed on a DC 16 Intelligence 
  (Religion) check, they know that boneclaws are bound 
  to a master, whom they rarely abandon.
  The characters can persuade the boneclaw to turn 
  against its master with a successful DC 20 Charisma 
  (Deception or Persuasion) check. If this occurs, the 
  boneclaw gives them the command word to open the 
  door in Area 5. After Varenius is slain, it wishes to return 
  to the Shadowfell.
  5. The Black Baron’s Domain
  As the characters approach the door, read or summarize:
  The Abyssal inscription reads: Honor the Lord of Bones 
  with a child and the way will open. Characters who pass 
  a DC 16 Intelligence (Religion) check know the door 
  depicts Myrkul creating undead for his legions.
  The door emits an aura of abjuration and necromancy 
  magic and can only be opened by casting animate 
  dead, create undead; a similar effect that produces an 
  undead creature; or by speaking the command word. If 
  a character creates an undead creature within 10 feet of 
  the door, they must make an opposed Charisma ability 
  check against Varenius. If they fail, the undead creature 
  is created as per the spell or effect, but is under Varenius’ 
  control.
  As the characters enter, read or summarize:
  The chamber is enchanted with a permanent mirage 
  arcane spell crafted to look like a small cemetery in 
  the Shadowfell where Varenius last met with Myrkul 
  before the god’s defeat. The chamber’s stone walls are 
  impassable, even though the illusionary terrain may 
  suggest otherwise. In addition to the illusionary terrain, 
  nonmagical light sources only emit dim light in a 5-foot 
  radius sphere, regardless of their normal statistics. The 
  only real object in the room is the sarcophagus in the 
  mausoleum along the eastern wall (see Treasure below 
  for more information).
  Creatures. Unless slain in Area 1, Varenius, a skull lord 
  (MToF p230) is in the area preparing for the characters. 
  He has summoned 5 skeletons (MM p272) using his 
  Legendary Action. The are also 3 ghouls and a ghast 
  You open the door to another, bleaker realm altogether. 
  Small tombstones and obelisks rise from the dying grass 
  in a small cemetery. Flowers are laid as offerings here and 
  there, but they are weak and sickly; the air itself seems 
  to drink light and color. The border of the cemetery is 
  a twisted mess of wrought iron fence and gnarled trees. 
  Although it is unremarkably decorated, your senses are 
  drawn to a single mausoleum.
  Adjusting this Encounter
  Here are some suggestions for adjusting this  
  encounter, according to your group. These are not 
  cumulative.
  • 
  Very Weak: Remove 2 shadows and reduce the 
  boneclaw’s hit points by 30.  
  • 
  Weak: Reduce the boneclaw’s hit points by 30.
  • 
  Strong: Increase the boneclaw’s grapple escape DC 
  to 16.
  • 
  Very Strong: Add 1 shadow and increase the 
  boneclaw’s grapple escape DC to 16.
  This large door is made from a single polished bone. 
  Due to its size, it must have been harvested from a giant or 
  dragon. The door is intricately carved to depict a scene of 
  a robed undead leading an army of skeletons. Behind them, 
  a nameless city crumbles. There is an inscription in jagged, 
  violent script along the frame.
  
  76
  (MM p148) who serve as Varenius’ personal servants. If 
  the wraith (MM p302) released by Varenius was forced 
  to retreat, it is in the area and has healed using Varenius’ 
  Master of the Grave trait.
  Tactics. Varenius casts fear and stays at range 
  attacking with damaging spells. If he is low on spell slots 
  or forced into melee combat, Varenius casts mirror image 
  and haste and attacks with his staff. Varenius uses his 
  Legendary Action to summon more skeletons if he has 
  fewer than 3 skeletons.
  Varenius and his undead minions fight to the death.
  Treasure. Varenius wears a gold crown inlaid with 
  rubies and onyx worth 850 gp and gold and platinum 
  rings worth 200 gp. He also carries a scroll of protection 
  against celestials.
  As the characters inspect the sarcophagus, read or 
  summarize:
  The Sarcophagus of the Forgotten is a powerful magic 
  item itself (see below for more information). Opening 
  the sarcophagus requires a successful DC 18 Strength 
  check. The sarcophagus’ lid weighs 600 pounds. Inside 
  is a headless humanoid skeleton wearing black plate 
  mail +1 and gripping a nine-lives stealer longsword with 
  5 charges remaining. If the sword is removed from the 
  sarcophagus for longer than 24 hours, the sarcophagus 
  loses its magical properties. The sarcophagus weighs 
  3,600 pounds and is impossible to move without magic, 
  complicated machinery, or a large labor force.
  Cursed Wand of Fear
  Wand, rare (requires attunement)
  The undead cleric of Myrkul who created this wand 
  wove a curse to ensure no living creature could use the 
  wand without joining Myrkul’s ranks. The wand functions 
  as a normal wand of fear (DMG 210) but carries the 
  following curse.
  Curse. After attuning to the wand, the wielder takes 
  1d6 necrotic damage whenever they finish a long rest. 
  This damage cannot be reduced in any way. The wielder’s 
  hit point maximum is reduced by an amount equal to the 
  damage taken. If this effect reduces the wielder’s hit point 
  maximum to 0, they die and rise as a wight in 24 hours.
  Breaking the Curse. The curse is permanently removed 
  from the item by submerging the wand in holy water for 
  five days. Each day a creature must whisper a peaceful 
  memory into the wand.
  Sarcophagus of the Forgotten
  Wondrous item, legendary
  Myrkul’s first order to Varenius was to bury each 
  of the three bodies used to create the skull lord. This 
  sarcophagus houses the remains of one of the cultists: a 
  warlord whose name has been forgotten.
  You can lay up to five Medium or Small humanoid 
  corpses at the base of the sarcophagus. After chanting 
  the prayer to Myrkul inscribed along the base of the 
  sarcophagus, you choose to create up to 5 ghouls, 2 
  ghasts, or 2 wights. Each undead creature rises from one 
  of the corpses near the sarcophagus and is under your 
  control.
  As a bonus action on each of your turns, you can 
  mentally command any creature you animated with this 
  item if the creature is within 120 feet of you (if you control 
  multiple creatures, you can command any or all of them 
  at the same time, issuing the same command to each 
  one). You decide what action the creature will take and 
  where it will move during its next turn, or you can issue a 
  general command, such as to guard a particular chamber 
  or corridor. If you issue no commands, the creature only 
  defends itself against hostile creatures. Once given an 
  order, the creature continues to follow it until its task is 
  complete.
  After using the sarcophagus in this way, it cannot be 
  used again for 7 days.
  The lid of this sarcophagus depicts a human male clad 
  in elegant but imposing plate mail gripping a longsword of 
  ancient craftsmanship. The hilt of the sword terminates in 
  a clawed skeletal hand gripping a cut gemstone.
  Adjusting this Encounter
  Here are some suggestions for adjusting this  
  encounter, according to your group. These are not 
  cumulative.
  • 
  Very Weak: Reduce Varenius’ hit points by 20, 
  remove 1 ghoul.
  • 
  Weak: Reduce Varenius’ hit points by 20 and reduce 
  the ghouls’ and ghasts hit points by 10 each.
  • 
  Strong: Increase Varenius’ hit points by 30 and 
  increase the ghouls’ and ghast’s hit points by 10 
  each.
  • 
  Very Strong: Increase Varenius’ hit points by 30, 
  add 2 ghasts 
  
  77
  Author Biographies
  Phil Beckwith
  Phil Beckwith is an IT Project Manager by day, owner 
  of P.B. Publishing by night, known mostly for many 
  bestselling and successful titles on the DMs Guild, 
  including the highly rated horror adventure  The Haunt, 
  the 200 page hardcover tome Adventure Anthology, and 
  a co-creator for the best-selling Monsters of the Guild. 
  Follow him on Twitter @PBPublishing1. 
  Chris Bissette
  Chris Bissette is an ENnie nominated writer and 
  cartographer. His work can be found on the DMs Guild, 
  DriveThruRPG, and LootTheRoom.uk. He is best known 
  for Breaker of Chains. Find him on Twitter @pangalactic. 
  He is probably standing behind you.
  Alex Clippinger
  Alex is a warlock living among us who has made a pact 
  with whatever entity is responsible for puns and pop 
  culture references. His work on the Guild includes Faiths 
  of the Forgotten Realms, The Faithful of Eberron, and 
  more. He can be found on Twitter at @Aclippinger or 
  summoned in a pentagram using chicken blood and dad 
  jokes
  Elise Cretel
  Elise Cretel works as a technical writer and editor in 
  nuclear engineering by day and D&D Dungeon Master 
  by night. Has played on a D&D podcast, D&D streams, 
  and enjoys interviewing the RPG community. Favorite 
  D&D class is Wizard and Psion. Also published through 
  HitRecord productions. @DNDElise on Twitter.
  Robert P Davis
  R P Davis is a wordsmith and voice artist. He has been 
  a tabletop gamer the entire time he’s been sentient, and 
  a role-playing addict for more than 30 years. In that time 
  he’s written countless things, from simple spell effects to 
  campaign worlds to complete role-playing games. He has 
  presented and participated in panels at sci-fi and fantasy 
  conventions alongside such luminaries as Kenneth Hite 
  and George R R Martin. He started writing for the Guild 
  in August 2016, and is best known for Mordenkainen's 
  Lost Notebook and You Can Try - Tips on becoming a 
  better DM.  Visit his website at www.r-p-davis.com or 
  follow him on Twitter @WP2XX.
  Ashley May
  Ashley May is a writer who found ways to pursue her 
  passions for worldbuilding, role-playing, and cooperative 
  storytelling, all within Dungeons & Dragons. Her works 
  can be found on dmsguild.com, and she is best known 
  for Festivals, Feasts, and Fairs, a guide to turning your 
  "pleasant downtime" into a fully interactive experience. 
  She prefers to take small, neglected subjects, throw 
  them under a microscope, and examine all of their facets 
  in minute detail. You can follow her on Twitter at @
  AshleyMayWrites.
  Luciella Scarlett
  Luciella Elisabeth Scarlett is an aromantic and asexual 
  author and illustrator based in Melbourne Australia, 
  who obnoxiously publishes under a name the length of 
  an entire alphabet. Her other RPG supplements can be 
  found on dmsguild.com, and she is best known for her 
  very silly dungeon crawl titled Yeryl’s Super Happy Fun 
  Murder Dungeon, in which a lonely beholder makes a 
  misguided attempt to make some new friends. You can 
  also follow her on Twitter or Facebook @luciellaes or at 
  luciellaes.wordpress.com.
  Christopher Walz
  Christopher Walz is the best-selling creator of The 
  Midnight Revelry and An Ogre and His Cake, a children’s 
  charity project, for the Dungeon Masters Guild. He 
  began his journey through roleplaying games when he 
  was 6 years old, looking at the pictures in his brother’s 
  Monstrous Manual. When he isn’t writing or killing his 
  players, he is trying to turn his son into a dungeon master 
  and looking for trolls in the wilds of Central Kentucky. 
  Follow him on Twitter @DMChristopherW.
  Micah Watt
  Owner of Pyromaniac Press, Micah is a successful 
  Pathfinder and D&D 5e designer, known widely for 
  his adventure path What Lies Beyond Reason, and the 
  epic D&D 5e hardcover deity supplement Faiths of the 
  Forgotten Realms. Visit www.pyromaniacpress.com, or 
  find him on Facebook or Twitter @pyromaniacpress.
  
SOURCE: textdata/thevault/Dungeons & Dragons [multi]/5th Edition (5e)/3rd Party/Pyromaniac Press/Pyromaniac Press - Undermountain The Lost Chambers.pdf