The Phalanx have infiltrated the X-Men by assuming the identities of several members. To save themselves, the team must allow their ship to be destroyed. Stranded in space, the X-Men must hatch a daring plan to survive.

In the sick bay aboard their cruiser in the Shi'ar Empire, the X-Men (Beast, Bishop, Rogue, Gambit and Joseph) treat Deathbird, the sole survivor of a starstation devastated by the Phalanx. Deathbird and Bishop are nearly attacked by two Phalanx posing as Gambit and Joseph, but she shoots them down.

Elsewhere on the ship, Phalanx have boarded and captured Gambit and Joseph. Rogue fights the aliens, but begins to succumb to a techno-virus, when Gambit breaks free and rescues her and Joseph.

In an interlude on Earth, Bastion arrives at his base with his captive, Jubilee [see Generation X #25].

Having defeated the boarders, the X-Men continue toward the heart of the empire, but their cruiser is destroyed by a Phalanx ship. The mutants and their allies, safely huddled in a pod held together by Joseph's power, drop to a planet with a Shi'ar outpost. From there, they teleport to the Shi'ar Throneworld.