The ultimate X-Men ensemble fights a war for the survival of the species across two time periods in X-Men: Days of Future Past. The characters from the original X-Men film trilogy join forces with their younger selves from X-Men: First Class in an epic battle that must change the past – to save our future. The X-Men send Wolverine to the past in a desperate effort to change history and prevent an event that results in doom for both humans and mutants.