Merge:Days of Future Past

Days of Future Past is the name of a popular storyline in the Marvel Comics comic book Uncanny X-Men issues #141 and #142. It deals with a dystopian alternate future in which mutants are incarcarated in concentration camps. An older Kitty Pryde transfers her mind into the younger, present-day Kitty Pryde, who brings the X-Men to prevent a fatal moment in history which triggers anti-mutant hysteria.

The storyline was very popular at the time and was produced during the franchise's meteoric rise to popularity, which was largely due to the Dark Phoenix Saga and Days of Future Past writer/artist team of Chris Claremont and John Byrne. As a result of this popularity, the dark future seen in this story was revisited later on several occasions.

Plot
The storyline alternates between the present day, in which the X-Men fought Mystique's new Brotherhood of Evil Mutants, and a future timeline caused by the X-Men's failure to prevent them from assassinating Senator Robert Kelly, in which robot Sentinels ruled the United States and mutants were forced to live in concentration camps. The X-Men were forewarned of this tragedy by the 2013 AD version of their teammate Kitty Pryde, whose mind travelled back in time and possessed her younger self to prevent this future from ever coming to pass. She succeeded in her mission and returned to the future. Despite her success, the future timeline from which she hailed still exists, but as an alternate timeline rather than as the actual future.

Rachel Summers, who was a key player in the original storyline, travelled through time to the present day and joined the X-Men. Nimrod, the "ultimate Sentinel", followed her to the present and became a foe of the X-Men and the Hellfire Club. Another supervillain, Ahab, later followed her to the present in the "Days of Future Present" crossover. Ahab kidnapped the children Franklin Richards (son of Mister Fantastic and the Invisible Woman, and in the future timeline Rachel's love) and Nathan Summers (son of Cyclops and Madelyne Pryor, and as an adult the mutant hero named Cable), but was defeated by the X-Men, X-Factor, the New Mutants and the Fantastic Four.

Meanwhile, Rachel joined the European mutant team Excalibur, whose series twice revisited the "Days of Future Past" timeline. The first time was in a story by Alan Davis, in which a time-travelling Excalibur and several Marvel UK heroes overthrew the Sentinel rulers of the future America. This storyline also revealed that Excalibur's robotic "mascot" Widget had been possessed by the spirit of the future version of Kitty Pryde. The second revisiting was after Rachel was lost in the timestream, and was only seen in a vision by her teammate Captain Britain. This story, "Days of Future Tense", revealed the final fate of the "Days of Future Past" timeline's Excalibur team.

By 2005, Official Handbook to the Marvel Universe: Alternate Universes 2005 has given the numerical designation of "Days of Future Past" Earth as Earth-811.

Animated series
The Days of Future Past storyline was adapted in the X-Men animated series, where its concepts were combined with another alternate-future story - that of Bishop and the idea of a traitor within the ranks of the X-Men. In the original comic book version of this story, this traitor was responsible for killing the X-Men, and was believed by Bishop to be Gambit - combined into the Days of Future Past plot, this traitor was made responsible for being the one who killed Senator Kelly, and turned out to be Mystique, merely imitating Gambit's form.

The future that Kelly's death led to was much the same as the comics - Sentinels went into mass production and were unleashed upon an unsuspecting mutant population. Every mutant on Earth was captured and led to concentration camps, but soon, the Sentinels decided that, in order to protect mankind, they would have to take over. Under the machines' tyrannical rule, the entire North American continent was soon turned into a wasteland, its human population living in fear of their robotic masters and its mutant population rendered almost extinct. Only a small group of mutant rebels remained free and unharmed, led by an aged Wolverine. In this future time of 2050, Bishop is not the mutant police agent that he is in his comics-future, but a bounty hunter who soon captures Wolverine and his team-mates; when the Sentinels betray him, however, he sides with Wolverine and the machinesmith, Forge, who has invented a time portal that he will use to alter history and prevent their nightmarish future from ever occurring. Bishop volunteers and travels back in time, only to arrive amensiac and pursued by the future super-sentinel, Nimrod. After an encounter with the present-day X-Men, a battle with Nimrod and a mind-scan by Professor X, Bishop's memory returns and he implicates Gambit as the traitor he has been sent to stop. Unsure of how to react, the X-Men travel to Washington to guard Kelly and wind up battling the Brotherhood of Evil Mutants. Their leader, Mystique, uses her shape-shifting powers to disguise herself as Kelly's aid and lure him away, before assuming Gambit's form and preparing to kill him, thereby implicating the X-Men as a national threat. The real Gambit arrives in time to stop her, but when Bishop finds himself confronted with two Gambits, he is about to shoot both of them for security's sake when Rogue stops him, tearing off the armband that keeps him anchored in time, hurling him back to his own future.

Arriving back in his future, it first seemed to Bishop that nothing had changed and that the world was still as he had left it, but he soon discovered that something had changed - a deadly plague now raged across the world, engineered by the ancient mutant, Apocalypse. Travelling back in time once more to stop the virus, Bishop succeeded, but the X-Men perished in the effort. This in turn caused the erasure of the future reality of 3999, home-time to the mutant mercenary Cable, who travelled back to before Bishop's arrival in the past and altered events once more to ensure the destruction of the virus, the survival of the X-Men and the preservation of both his and Bishop's timelines.

When the time-portal-generating mutant Trevor Fitzroy was assigned the task of travelling back to the mid-20th Century and killing a young Professor X, his actions created an alternate present (analogous to the comic book's Age of Apocalypse). Bishop and his sister, Shard travelled to this time and teamed up with the alternate versions of Wolverine and Storm, undoing Fitzroy's actions. As the siblings returned to their own time, Shard emerged through the portal, but Bishop was cast off-course by a temporal anomoloy - in 3999, Apocalypse has wrested the power of time-travel from Cable, and his transit through the timestream clashed with Bishop's, hurling them both into limbo, the "axis of time." There, Bishop was pestered by the maniac "janitor of time," Bender (actually the disguised form of the Avengers foe, Immortus) while Apocalypse mastered the axis's ability to touch all times, forming a complex plot to re-write time using the combined power of captured psychic mutants. Bishop was instrumental in putting this scheme to a stop, liberating some of the psychics at a key juncture, who then used their powers to banish Apocalypse from the timestream.

As of the end of the series, the storyline remains unresolved, with nothing having having been shown to alter Bishop's future from the dystopia seen in Days of Future Past.

X-Men: The Last Stand
The Days of Future Past reality is hinted at in the opening sequence of the motion picture, X-Men: The Last Stand, as Wolverine and Storm teach a Danger Room combat session, in which the battlefield is a devastated city, and their opponent, a Sentinel.

Trivia
The first issue of this storyline was voted 25th greatest Marvel Comic of all time by the fans in 2001.