Xavier is saved by the Morlocks, but Callisto cannot keep her promise to Storm when Morlock children are killed by mutant haters. Jimmy Proudstar means to avenge his brother's death (John Proudstar, aka Thunderbird) as he ambushes Banshee and sets his sights on Professor X. To get Banshee back, the X-Men must infiltrate Cheyenne Mountain, but their mission goes wrong when Empath sounds the alarm and turns the military against the X-Men. Nimrod tries to fit in as he tries to figure out what went wrong with his time travel.
First appearance of Firestar.