It’s the big Bishop issue, where he joins the team.
As a new character, this issue is a helpful way of learning his power set.
It’s basically one long gun fight with Bishop and his allies against the mutants of the future.
Also, in a flash-forward to the future that Bishop comes from, we see a video of Jean Grey warning that there is a traitor among Charles Xavier’s mutants–but it’s not clear at what point in time Jean made the recording.
Creators: Scott Lobdell, Jim Lee, John Romita Jr.