After the re-emergence of the world's first mutant, world-destroyer Apocalypse, the X-Men must unite to defeat his extinction level plan.

Before Charles Xavier and Erik Lensherr took the names Professor X and Magneto, they were two young men discovering their powers for the first time. Before they were arch-enemies, they were closest of friends, working together with other mutants (some familiar, some new), to stop the greatest threat the world has ever known.