Approaching the World, the mysterious headquarters of Weapon Plus, the parent company of Weapon X, Cyclops, Fantomex, and Wolverine discover that a massacre has occurred. An extremely powerful subject known as Weapon XV has escaped and attacked a battalion of A.I.M. soldiers seeking to capture the compound. In search of Weapon XV, the X-Men enter "the World", a place where time is at the mercy of Weapon Plus. And what is the link between Wolverine and Weapon XV?