Xavier's School ... Under Siege! The X-Men ... Abducted!
Now pawns of the mysterious Weapon X program, the mutant heroes' only hope lies with the one team member to evade capture: the enigmatic, unproven Wolverine. Can Logan go it alone against the shadow-ops organization that transformed him into one of the world's most lethal killing machines? To succeed, he must survive an adrenaline-charged, adamantium-laced brawl with the savage Sabretooth - a predator every bit his equal.
The second Ultimate X-Men story arc, "Return to Weapon X" features the Ultimate-universe debuts of Nightcrawler, Juggernaut, Rogue, and Nick Fury - and the return of the Brotherhood of Mutants.
Collecting Ultimate X-Men #7-12.