Superstar Warren Ellis teams with hot newcomer Trevor Hairsine (Ultimate Six) to tell a story of international intrigue that shakes every Ultimate book to its core! As world communications systems break down, the source of the anomaly is revealed as Tunguska, Russia. Nick Fury of S.H.I.E.L.D. leads a force comprised of Captain America, Black Widow, and Sam Wilson to investigate, while, simultaneously, Charles Xavier of the X-Men dispatches his own team consisting of Jean Grey, Wolverine, and Colossus. And what they discover there - and what happens next - defies belief!

Collecting: Ultimate Nightmare 1-5