Mentallo has taken over Monster Island and is controlling the minds of all the inhabitants. He already sent Fin Fang Foom to tear apart Tokyo, but what are his plans for the rest? And can three X-Men and one X-Man-In-Training stop a dozen mind-controlled monsters if Emma can’t get in Mentallo’s head? And if that’s not enough, one of the X-Men is changed forever. This is not a what-if, it is for real!