Friend or Foe?

The X-Men--mutant protectors of a world that fears and hates them. The Avengers--Earth's mightiest heroes, the greatest superteam ever assembled. Now they have joined forces with the incredible Hulk against the deadly Leader, having traced him to his base on the moon.

But the gamma-powered super-genius's plans may be more than even they can handle, for the Leader has brainwashed Rogue, Wolverine, and the Scarlet Witch to fight for him. With them, the Gamma Sentinels, his own brilliance, and another mysterious ally at his side, the Leader may be, able to defeat the combined forces of Marvel's greatest super-teams!