The critically acclaimed, fan-favorite storyline that rocked the X-Men Universe to its core starts here! Legion, the supremely powerful son of Charles Xavier, wants to change the world - and he's traveled back in time to kill Magneto to do it! Can the X-Men stop him, or will the world as we know it cease to exist? Featuring the last day of Cable's life; Gambit vs. Sabretooth; the beginning of Archangel and Psylocke's relationship; and Mystique, bent on revenge! Witness the final moments in the lives of the X-Men before their world changes forever! Collecting X-FACTOR #108-109, UNCANNY X-MEN #319-321, X-MEN #38-41, CABLE #20 and X-MEN: AGE OF APOCALYPSE ASHCAN EDITION.