The X-Men's past, present and future collide in this 50th anniversary event! Something horrible happens to the past versions of the X-Men that shakes spacetime to its core - and more X-Men arrive from the future with a message: The original five must return home! But when young Cyclops and Marvel Girl run away to stay in the present, the hunt is on! And where does the modern-day Cyclops' revolutionary faction fit in? Things get even more complicated when mysterious foes attack the Jean Grey School and the healing-impaired Wolverine takes mortal hit! With space-time up for grabs, the surprise ending will change everything, as the X-Men's footing in the world is drastically altered! COLLECTING: All -New X-Men 16-17, Uncanny X-Men 12-13, Wolverine & The X-Men 36-37, X-Men: Battle of the Atom 1-2, X-Men 5-6