After years of planning and waiting, the frightening Isolationist finally leaves his castle of ice to hunt down the man known as Jamie Madrox in X-Factor #21. But is the Isolationist a friend or foe to the X-Factor? Legendary writer Peter David and fan favorite artist Pablo Raimondi present an issue of mystery and suspense with Marvel's most unusual team of mutants. But even the most ardent X-Fan may not know that The Isolationist made his debut back in the pages of X-Factor (vol. 1) #89, when David hinted at the agenda of this shadowy figure. Now a decade's long mystery will be revealed…and will leave the members of X-Factor reeling!

As if the appearance of the Isolationist wasn't enough, the members of X-Factor all cope with surprising new developments; Rictor springs into action, Siryn and Monet accept a new case, Guido receives a job offer, and Layla discovers something that will shock the entire team!

Also, X-Factor #21 features part three of X-Men: Endangered Species, the epic quest of one mutant—the famous X-Man Beast—trying to solve the puzzle of mutant extinction before time runs out! This can't miss chapter is written by Mike Carey (X-Men) and penciled by Mark Bagley (Ultimate Spider-Man).

Be sure to pick up a copy of X-Factor #21 to learn about all the exciting developments in Mutant Town!

X-FACTOR #21 (MAY072158)
Written by PETER DAVID & MIKE CAREY
Pencils by PABLO RAIMONDI & MARK BAGLEY
Cover by PABLO RAIMONDI
Rated T+ … $2.99
FOC—6/21/07, On-Sale—7/11/07

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