The death of Jean Grey re-defined the X-Men, but her resurrection did nothing less! Recovered by the Avengers and revived by the Fantastic Four, Jean's return re-grouped her fellow founders into a supposed mutant-hunting unit that ferreted out some of mutantdom's rising stars - including the devastating debut of the ancient evil everyone identifies as Apocalypse! With Mystique, the Morlocks, and the Master Mold! Featuring tie-ins to the infamous Mutant Massacre! Guest-starring Thor and Power Pack! Collects X-Factor #1-16, Annual #1, Avengers #263, Fantastic Four #286, Thor #373-374 and Power Pack #27.