X-Men: Days of Future Past ending explained: Undoing X-Men's biggest mistake

Fox's classic X-Men franchise had many highs, but its crown jewel might just be X-Men: Days of Future Past. The franchise struggled with where to go after its initial trilogy ended in controversial fashion, so it split off in two different directions: Telling old stories in the past via a new prequel movie, and continuing the current stories through the Wolverine spinoff saga. This one, however, brought both stories together in what can only be described as a masterclass in storytelling.

Released in 2014, Days of Future Past adapted one of the X-Men's most iconic storylines and it featured the casts from both chapters of the X-Men movies in order to make it happen. It was fronted by Hugh Jackman, who returned to the role of Logan / Wolverine, and he was joined by his fellow returnees Patrick Stewart, Ian McKellen, Shawn Ashmore, and Elliot Page (along with a few other surprises). But it was the X-Men: First Class cast who mostly joined Jackman as the film's primary characters, with James McAvoy, Michael Fassbender, Jennifer Lawrence, and Nicholas Hoult all returning too.

The film notably adapted the source material in a way that felt loyal to the Fox film series while also undoing some of the damage that previous installments had done to it.

Logan successfully saves the future

The entire basis upon which X-Men: Days of Future Past is built is that Logan must save the mutants (and the humans) from a dystopian future in which Sentinels have eradicated them. To make that happen, he must go back in time to convince friends-turned-enemies Charles Xavier (a.k.a. Professor X) and Erik Lenscherr (a.k.a. Magneto) to team up and stop Mystique from killing Bolivar Trask and setting that future in motion. As impossible a task as that seemed, he successfully pulled it off (even with Magneto attempting to do his own thing), creating a better future for all mutants in the process.

When he awoke in the future again, Logan discovered that the changes he helped make in 1973 had made an impact. Professor Xavier's School For Gifted Youngsters was up and running again, peace had been restored, and mutants were thriving, all because of his actions in the past. And because of its failure in the 1970s, the Sentinel program never evolved into the unlimited supply of unstoppable killing machines that it did in the original timeline.

In this new timeline, Logan teaches at the school, but he doesn't necessarily remember that, as his last memory was of 1973. When he reveals this to Professor X, Charles simply smiles as he realizes that the version of Logan who helped him all those years ago had "woken up" in the new timeline and we can only imagine the conversation they had after that to catch up, likely explaining the differences of their respective timelines to each other. And presumably, Charles could make Logan remember the new life he had lived since.

How Jean Grey and Cyclops are alive in X-Men: Days of Future Past

One of the biggest moments in the concluding scenes of X-Men: Days of Future Past came when Logan was making his way through the mansion and saw a woman with long red hair standing before him. Could it be? Was it, really? Yes! It was Jean Grey, alive and well, with Famke Janssen having returned to play the role. And just when Logan went to say hi, he was interrupted by Scott Summers, with James Marsters reprising the role. And yes, Logan was even happy to see him.

There's a lot to be said about this scene, and it's all good; the reason being that it undoes a lot of the damage done by 2005's X-Men: The Last Stand. The movie was incredibly divisive as it saw Jean Grey's Phoenix persona kill Cyclops early on in the film, doubling down on the trilogy's constant underutilization of that character, before Logan had to ultimately kill her in the final scenes. Fans were not happy with the original trilogy's dark ending and longed for it to be undone; to see that actually happen, in an adaptation of such a classic X-Men storyline no less, was just the icing on the cake and the perfect ending to an incredible movie.

Logan's actions in the past had changed their future, and that meant that Jean and Scott didn't suffer the same fates that they did in the original timeline. It was a welcome change, and one that also gave the ongoing saga of prequel movies much more creative freedom to tell its own stories now that they were all taking place in this new timeline.

And speaking of changes, another welcome one was that Rogue was back at the Mansion, still in a relationship with Bobby Drake, a.k.a. Iceman, and seemingly hadn't taken the cure to remove her mutant abilities. It was a cameo appearance for Anna Paquin, but one that gave the iconic Marvel character a future that fans were more satisfied with, undoing yet another controversial story from The Last Stand.

Mystique rescues Logan, posing as William Stryker

Mystique was at the center of X-Men: Days of Future Past. It was a decision that she made to kill Trask in the original timeline that ultimately kickstarted the push towards bringing his Sentinels to life and so it was imperative that Logan lead the younger X-Men in stopping her from making that same mistake in the new timeline that was forming.

When Magneto tries to kill the humans (along with Trask), she steps up to stop him. And even though she considered killing them too, she allows Charles to talk her out of it, giving the humans the impression that their lives were spared by a mutant, which created a new timeline in which the Sentinel program is scrapped.

Logan, meanwhile, had been trapped in rebar at the bottom of the ocean by Magneto until he was seemingly pulled from the water by the young William Stryker, seemingly setting him on a similar path to his original timeline; except it wasn't Stryker, as his eyes glowed yellow whenever he saw him, very much implying that it was Mystique in disguise.

We don't know all of what happened to Logan between 1973 and 2023 in this timeline, but he finds his way back to the X Mansion and even gets a career out of it, teaching history to young mutants. None of that would have been possible if Raven hadn't found him at the bottom of the ocean. And there's an irony in that, as Logan went back in time to save Mystique from her former past, and she returned the favor by saving him from his future.

The Age of Apocalypse begins in the post-credits scene

While Marvel Studios was the undisputed leader of pivotal post-credits scenes by the time that X-Men: Days of Future Past came out, that didn't stop the Fox franchise from trying their hand at it. And what a scene it was, as it sets up its own sequel with the first live-action appearance of one of the X-Men's most notorious villains.

The scene, which is set in ancient Egypt, features a young mutant elevating pyramids in front of an audience chanting his name, all while four horsemen watch from afar. The name they are chanting is "En Sabah Nur" which is a name that sends chills down the spines of comic book fans. This is the first appearance in the franchise for the mighty Apocalypse and his Four Horsemen, setting the stage for his arrival in the present (or, well "past") and his eventual showdown with the X-Men.

This post-credits scene lays the groundwork for sequel X-Men: Apocalypse, which was released in 2016. Oscar Isaac joined the franchise as Apocalypse himself, and fought the young X-Men, with the younger cast members of the prequel films returning. Needless to say, an all-out battle against the villain and his horsemen ensue, with the fate of humanity and mutantkind hanging in the balance.