When the Dark Phoenix rises, suns grow cold and universes die! Gathered by Charles Xavier, the X-Men have dedicated their wondrous abilities to protect mankind — even those who hate and fear them. Now, these incredible individuals embark on an adventure that will span the expanse of the cosmos. One of their own, Jean Grey, has unwittingly attained power beyond conception — and been corrupted, absolutely. The X-Men must decide: Is the life of the woman they cherish worth the existence of an entire universe? Collecting X-MEN #129-138, CLASSIC X-MEN #43, BIZARRE ADVENTURES #27, PHOENIX: THE UNTOLD STORY and WHAT IF? (1977) #27.