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.

In the near future, a weary Logan cares for an ailing Professor X in a hideout on the Mexican border. But Logan's attempts to hide from the world and his legacy are upended when a young mutant arrives, pursued by dark forces.