The X-Men Storyline That Is Too Dark For A Live-Action MCU Adaptation

In the decades since their debut in 1963, the X-Men have evolved into powerful metaphors for marginalized groups facing bigotry and discrimination, and their most powerful stories are tinted with darkness. In "Days of Future Past," Kitty Pryde travels back in time to foil an assassination that will lead to mutantkind's extermination. Meanwhile, "God Loves, Man Kills" sees the X-Men unite with Magneto to stop televangelist William Stryker, who preaches for the destruction of mutants.

Impressively, these incredibly dark storylines have been adapted into some of the best X-Men movies ever made, albeit with some of the sharper edges sanded off (Stryker is not a televangelist in "X-Men 2: X-Men United," for example, but a U.S. Army Colonel). As the Marvel Cinematic Universe prepares to reboot the X-Men film franchise, one story is perhaps too dark to appear on the big screen: "Mutant Massacre."

Published in 1986, "Mutant Massacre" begins in "Uncanny X-Men" (vol. 1) #210. The mutant mercenaries known as the Marauders brutally attack the Morlocks, a mutant society living in Manhattan's subway tunnels. The X-Men stop the massacre, but at a great personal cost. With hundreds of innocent mutants slaughtered, villains driven away but not defeated, and X-Men who barely survive the experience, this grim story is probably not what most want out of an MCU X-Men movie.

Hitting comic book shelves like one of Cyclops' optic blasts, "Mutant Massacre" was the biggest X-Men story published to date. Primarily plotted by Chris Claremont, Louise Simonson, and Walter Simonson, it spanned 12 issues across six different Marvel Comics titles ("Uncanny X-Men," "X-Factor," "New Mutants," "The Mighty Thor," "Power Pack," and "Daredevil"), making it the first crossover event in X-Men history. The labyrinthine plot splits into several directions, with the X-Men and X-Factor teams separately fighting the Marauders.

In "X-Men," Wolverine has his first clash with his archenemy Sabretooth, Kitty Pryde is struck by a Marauder's energy harpoon, and Colossus kills the rampaging Riptide. "X-Factor" sees Angel's wings impaled and pinned to a wall, though the intervention of Thor and Power Pack saves the team from more casualties. The teenage heroes of "New Mutants" aid the wounded Morlocks at the Xavier Institute, but are traumatized by the horrors brought into their home; meanwhile, Daredevil encounters a fleeing Sabretooth in the sewers.

"Mutant Massacre" unfolds at a breakneck pace, with eye-grabbing action scenes penciled by artists John Romita Jr., Walter Simonson, and Sal Buscema. The storyline is a powerful and intense read, unflinching in its portrayal of the Marauders' sadism and plunging the X-Men into a dark new era that would change them forever. 

The Mutant Massacre's impact was felt for years. One consequence was two injured X-Men — a comatose Nightcrawler and a now permanently intangible Kitty Pryde –- leaving to recuperate and form the British superhero team Excalibur. Another consequence? The amputation of Angel's wings, leading to Apocalypse transforming him into Archangel to serve as one of his Four Horsemen. Surviving Morlocks formed the terrorist group Gene Nation, with one massacre survivor, Marrow, joining the X-Men. And Gambit, introduced years after the original storyline, was revealed as the man who led the Marauders to the Morlocks, unaware of their true intentions.

In the real world, "Mutant Massacre" was a groundbreaking success, and one Marvel was eager to repeat. The X-Men barely had time to lick their wounds before "The Fall of the Mutants" in 1987 and "Inferno" in 1988. Four decades later, crossovers are almost a yearly event for the X-Men and their fans.

"Mutant Massacre" sees the X-Men at their darkest. While an era-defining story for Marvel's mutants, it is difficult to see it being adapted into blockbuster entertainment. Sure, "Avengers: Infinity War" ended with Thanos snapping half the universe out of existence, but audiences knew that the heroes would reverse it in the sequel. "Mutant Massacre," on the other hand, is as cold and final as it gets.