The Ultimates vs. the Ultimate X-Men: the battle begins! When the X-Men do the worst thing they could to humanity, the government orders Captain America, Iron Man, Thor, and the rest of the Ultimates to bring them down. A small but lethal army, the Ultimates were created to face these and other newly rising threats to mankind. But the X-Men's founder, Professor X, hasn't been training his students for nothing - and the young mutants just might take out the Ultimates first. Next, with the X-Men still licking their wounds from their battle with the Ultimates, can Professor Xavier's mutant team possibly survive the return of their most powerful foe? Witness the return of Magneto! Collects Ultimate War #1-4, and Ultimate X-Men #26-33.