Collects New Mutants (1983) #55-61; Uncanny X-Men (1981) #220-227; X-Factor (1986) #18-26; Captain America (1968) #339; Daredevil (1964) #252; Fantastic Four (1961) #312; Incredible Hulk (1968) #336-337, 340; Power Pack (1984) #35. The X-Men and their allies face war on every front! X-Factor comes up against their deadliest challenge yet in Apocalypse and his Horsemen, including the all-new - and all-too-familiar - Archangel! The New Mutants lose one of their own on an island of horrors! The X-Men take on the lethal Marauders - and the survivors will be asked to sacrifice themselves to stop the demonic Adversary! Featuring tie-ins starring Captain America, Daredevil, the Fantastic Four, the Hulk and Power Pack, this is one of the most devastating X-Men crossovers of all time!