Collects Uncanny X-Men #125-128, Classic X-Men #32-33 and 36. One of the X-Men's greatest allies must face her darkest secret when a child born of violence bends reality to his whims! The paranormal Proteus battles the X-Men in body and soul, shaking the psyches of even their strongest! But as Marvel's mightiest mutants face one world-threatening wonder, an even worse one awaits as the stage is set for the debut of Dark Phoenix!