"Mutant Massacre" was a 1986 Marvel Comics crossover storyline. It primarily involved the superhero teams the X-Men and X-Factor. The solo hero Thor, the New Mutants, Power Pack and Daredevil crossed over for an issue each in their own comic books. The crossover was a surprise success, yielding sales boosts to the mutant-based books and prompting Marvel Comics' long-running policy of holding such mutant crossovers annually. Plot The mysterious Marauders attack a mutant named Tommy and her Hellfire Club boyfriend in Los Angeles for the purpose of following her back to New York and finding the location of the underground mutant community known as the Morlocks. The Marauders kill Tommy and hundreds of Morlocks before the X-Men and X-Factor teams arrive separately and fight them, avoiding the total slaughter of the Morlocks. The two teams however do not meet during the battle and suffer crippling losses: X-Factor's Angel is crucified by the Marauders, while the X-Men's Colossus, Shadowcat, and Nightcrawler are all severely wounded. X-Factor's casualties are less due to the arrival of Power Pack and Thor, who help save the horribly wounded Angel and the rest of X-Factor from suffering any additional harm. Thor uses his powers to cleanse the dead from the Morlock tunnels with fire, which causes problems for the X-Men, who briefly believe that the firestorm was caused by the Marauders and believe that the New Mutants died in said fire. Several Morlocks, including Berzerker and Masque, make their way into the surface world and begin to work for their personal aims. Meanwhile, Wolverine saves the Power Pack and Healer from the Marauder Sabretooth. After their clash, Sabretooth follows Logan home to the X-Mansion. He destroys Cerebro, but is kept from hurting the other Morlocks when Psylocke engages Sabretooth in battle. Wolverine and the rest of the X-Men arrive, and Sabretooth falls off a nearby cliff in order to escape the X-Men, pursued into the water by Wolverine. As the fight continues in the ocean, Psylocke is able to glean some information about the Marauders from Sabretooth's mind. Reading order Uncanny X-Men Uncanny X-Men #210 (Prologue) Uncanny X-Men #211 New Mutants #46 Uncanny X-Men #212 Uncanny X-Men #213 X-Factor X-Factor #9 (Prologue) X-Factor #10 Thor #373 Power Pack #27 Thor #374 X-Factor #11 Daredevil Daredevil #238 is set after the events of the Mutant Massacre. The issue features Daredevil fighting Sabretooth after his escape from the