Collects X-Factor (1986) #112-126, Sabretooth and Mystique #1-4, Marvel Fanfare (1996) #6 and material from X-Men Prime (1995) #1. Fan-favorite shapeshifter Mystique and the savage Sabretooth join X-Factor! An out-of-control Alex Summers is wreaking Havok - and X-Factor is on his trail, including new members Mystique and Wild Child! But can Raven Darkholme be trusted? Maybe, with a nanotech inhibitor in her skull courtesy of teammate Forge! As the sinister Dark Beast from the Age of Apocalypse schemes in the shadows, Havok has a showdown with Random - and Alex decides to walk away from X-Factor, leaving Polaris heartbroken! The holographic Shard joins the team in time for the Adversary to return to haunt Forge! But when the government adds Sabretooth to the line-up, X-Factor's roster will be more dangerous than ever - perfect for the dark days that lie ahead!