The Case Files of Lord El-Melloi II

 is a Japanese light novel series written by Makoto Sanda ("Rental Magica") and illustrated by Mineji Sakamoto. Officially part of the "Fate" series, it began serialization by Type-Moon under the "Type-Moon Books" imprint on December 30, 2014 to May 17, 2019. The novels are set between the events of "Fate/Zero" and "Fate/stay night", focusing on Lord El-Melloi II, a former master who now investigates several mysteries after his participation in the Fourth Holy Grail War.
Two media adaptations were officially made: a manga adaptation by Makoto Sanda with illustrations from Tō Azuma began serialization in Kadokawa Shoten's "Young Ace" magazine on October 4, 2017 and an anime adaptation by Troyca, which adapts the "Rail Zeppelin" chapter, aired from July 6 to September 28, 2019.
Story.
Taking place 10 years after the events of Fourth Holy Grail War and 2 months before the events of "Fate/stay night", the story focuses on Lord El-Melloi II, formerly known as Waver Velvet, a successor of Kayneth and former master in the last Grail War, who is now a professor under the ranks of the Mage's Association. In his years as a professor in the Clock Tower, he is acting as the temporary head of the El-Melloi household until a proper successor can take over. When strange mysteries involving magic start occurring throughout London, he teams up with his apprentice, Gray, to solve these magical cases and expose the hidden conspiracies that drive the Mage’s Association.
Media.
Novel.
"The Case Files of Lord El-Melloi II" was written by Makoto Sanda, considered to be his first work after being approached by Type-Moon. During a session of tabletop RPG game "Red Dragon", alongside Nasu and Gen Urobuchi, Nasu asked Makoto if he could actually write a story for the Fate Series. It was then on "TYPE-MOON FEST" in July 2012 that Nasu asked Makoto to write a story for Waver Velvet/Lord El-Melloi II, on which he agreed. The first novel was first published by Type-Moon under their "Type-Moon Books" label on Comiket 87 on December 30, 2014. The tenth and last was published on May 17, 2019. It was illustrated by Mineji Sakamoto. Kadokawa Shoten later released the novels in a paperback edition.
A sequel novel series titled was announced in December 2019. The first volume was released on December 25, 2020.
Manga.
A manga adaptation by Makoto Sanda with illustrations from Tō Azuma began serialization in Kadokawa Shoten's "Young Ace" magazine on October 4, 2017. As of March 2021, seven volumes have been released so far.
Anime.
An anime adaptation of the novels, which only adapts the "Rail Zeppelin" storyline under the title was announced at the "Fate Project New Year's TV special" and animated by Troyca. Makoto Katō directs the series with Ukyō Kodachi as its writer, while Yuki Kajiura composes the music for the series. Jun Nakai is the character designer, while Ei Aoki is credited as supervisor. It aired from July 6 to September 28, 2019 on Tokyo MX, BS11, GTV, GYT, and MBS. Kajiura composed the series' opening theme song "starting the case: Rail Zeppelin", while ASCA performs the series' ending theme song , with lyrics written by Kajiura. Aniplex of America and Crunchyroll streamed the series in North America, Central America, South America, the United Kingdom, Ireland, Australia, and New Zealand. AnimeLab streamed the series in Australia and New Zealand. Funimation also simulcasted the series in their streaming site in North America. On October 3 2020, which is Waver's birthday, Aniplex of America announced they will be releasing the series in a Blu-ray box set with a full English dub. The set was released on December 15, 2020.
Video games.
Characters of the novel series also appeared in Delightworks's mobile role playing game "Fate/Grand Order" as special servants based on the characters. Waver Velvet/Lord El-Melloi II is a main five-star Caster-class Servant under the name of Zhuge Liang and has appeared in the "Fate/Accel Zero Order" event as a main character and guide. Gray, Reines (under the name of Sima Yi) and Luvia (under the name of Astraea) all begin as servants from the "Lady Reines' Case Files" collaboration event. Both Gray and Luvia are four-starred Assassin and Ruler class Servants respectively, however Reines is a five-star just like her adoptive older brother, in the Rider class.
Stage play.
A stage play adaptation based on the novel's "Adra Castle Separation" chapter, began on December 14, 2019 and concluded on January 19, 2020. Voice Actors Daisuke Ono, Akio Ōtsuka and Takumi Yamazaki, who voice Add, Rider (Iskandar) and Kayneth El-Melloi Archibald respectively, reprised their roles for the play. Limited release of the musical was released on blu-ray July 8, 2020. 