For Black History Week.
Back in Uncanny X-men #170, Angel had been kidnapped by the Morlocks to be their leader, Callisto's, love slave (hey thar Claremont) and Kitty is dangerously ill, thanks to the Morlock Plague. Which leaves the X-men with no choice - the only way to save their friends is to claim the right of leadership over the Morlocks and the only way to do that is by defeating Callisto. Step forward... Nightcrawler! But apparently the leader of the X-men has other ideas...
Lesson #1 in Don't Fuck With Storm class.