The Mutant Massacre story arc was a giant crossover event that included characters from all facets of the Marvel Universe. Aside from the obvious X-Men, the event included the X-Factor, Thor, The New Mutants, Power Pack, and Daredevil. This story arc, like so many other X-Men greats, was created by Chris Claremont.
The story begins as the titled Marauders take it upon themselves to attack a mutant named Tommy. While this may appear to be easy, it wasn’t as they wound up following him from Los Angeles to New York. It was in the latter of the two cities that the Marauders found the Morlock’s.
Not everyone is ok
Upon finding the Morlocks, the Marauders did what they do and made short work of them. Along with Tommy, they proceeded to massacre the majority of the Morlocks.
In an effort to prevent any further damage both the X-Men and the X-Factor arrive. Unfortunately, things do not turn out as plan and Angel is pinned to the wall by Harpoon and Blockbuster. The resulting attack left him with damaged wings. This would, of course, lead directly into his transformation into Archangel at the hands of Apocalypse.
To add insult to injury, along with the destruction of Angel, Shadowcat ends up trapped in her own mutant ability, and both Colossus and Nightcrawler are left wounded and exhausted.
Luckily for the team, Thor and Power Pack come to their aid.
Meanwhile, Sabretooth overthrows Rogue and makes his way into the X-Men Mansion. While in the mansion, he takes it upon himself to destroy the ever-important machine, Cerebro. Before he can do any more damage, the new arrival, Psylocke, takes it upon herself to try and stop the savage mutant. Unfortunately, as she would soon learn, she was outmatched by the stronger and larger Sabretooth. What this did allow for, however, was some time for Wolverine to arrive and attempt to stop him.
The arrival of Storm, Callisto and Magneto signified a turning point in the battle. Not only were the three able to provide additional support for the outmatched teams, this gave Psylocke the moment she required to probe his mind and figure out who orchestrated this attack. With this information in hand, she passes it off to Wolverine, who by now had battled Sabretooth to the edge of the nearby lake. This lake provided Sabretooth with the opportunity that he needed to escape the battle.
With the battle over and the Mutant Massacre concluded, the X-Men and remaining Morlocks leaned heavily on the shoulders of Moira MacTaggert. She provided them with an outlet to heal their wounds, regroup and begin to pick up the pieces of their shattered lives. This event also became a proving ground of sorts for Psylocke and at its completion, she was made a member of the X-Men.
The aftermath of this event cannot be understated. In the lore of the X-Men, this was just one of a few times where innocent mutants were slaughtered by one of their own. Worse yet, they were slaughtered for no true reason. This event left those affected by it a shell of the people they had once been. In fact, many years later, it was revealed that Mr. Sinister was behind the attack and he had used the X-Man, Gambit to orchestrate it.
The Mutant Massacre revelation about Gambit was a major sticking point in the history of Gambit. Because of it, he stood trial and was temporarily exiled from the team.