The storyline was produced during the franchise's rise to popularity under the writer/artist team of Chris Claremont, John Byrne and Terry Austin.

On the eve of a feared nuclear holocaust, the few remaining X-Men, while making a desperate attempt to stop the Sentinels, send Kitty Pryde's mind backward through time, to possess the body of her younger-self and to prevent a pivotal event in mutant–human history and the cause of these events: the assassination of Senator Robert Kelly along with Charles Xavier and Moira MacTaggert by Mystique's newly reassembled Brotherhood of Evil Mutants.

[2] Working with the present-day X-Men, Kitty Pryde's future-self succeeds in her mission and is pulled back to her own time, while her present-day-self is returned with no memory of any interim.

The world of 2013 is not shown again in this story arc; the present-day X-Men are left to ponder whether their future dystopia has been averted or simply delayed.

[3] John Byrne devised the plot for "Days of Future Past", since he wanted to do a story featuring the Sentinels and his collaborator Chris Claremont had no interest in coming up with one.

[7] The miniseries Days of Future Past: Doomsday looks at what happened to other characters as this world fell apart, such as Spider-Man being beaten to death in an anti-mutant riot or General Ross and the Avengers resigning from the government in protest at what they were being asked to do.

Numerous actors from the franchise returned, including Hugh Jackman, Halle Berry, Ian McKellen, Patrick Stewart, James McAvoy, Michael Fassbender, Anna Paquin, Elliot Page, Shawn Ashmore, Daniel Cudmore, Nicholas Hoult, Jennifer Lawrence, and Lucas Till.

[11] In this film, the catalyst for the Sentinel-dominated future was Mystique's assassination of Bolivar Trask and her subsequent capture, with analysis of her DNA allowing humanity to devise Sentinels capable of adapting to any mutant power.

After Shadowcat learns how to use her abilities to 'phase' someone into their past self, Xavier and Magneto decide to have her send someone back in time to the year 1973 to prevent Mystique from killing Trask, with Wolverine being selected as he is the only one who can survive the process due to his regenerative healing factor.

Upon arriving in 1973, Wolverine locates the past versions of Xavier, Hank McCoy, and Magneto and convinces them to help him prevent their extinction.

As a result, Mystique is hailed as a hero, the Sentinel program is scrapped, and Trask is arrested for selling his designs to foreign nations.