One triumphant return, one diabolical debut! When Jean Grey is found alive — with a little help from the Avengers and Fantastic Four — she reunites with the rest of Xavier's original class to form X-Factor! But as Cyclops, Marvel Girl, Beast, Angel and Iceman face new enemies Tower and Frenzy, little do they realize the villains are part of an Alliance of Evil led by…Apocalypse! They'll fight Iron Man and Spider-Man, encounter uncanny foes such as Bulk and Glow Worm, and take on old sparring partners in Freedom Force — but there's no question who will rise to the role of X-Factor's arch-nemesis. The story of En Sabah Nur begins here! Collects Avengers (1963) #263; Fantastic Four (1961) #286; X-Factor (1986) #1-9, Annual #1; Iron Man Annual #8; Amazing Spider-Man (1963) #282 and material from Classic X-Men #8, 43.