The mutant population is being devastated by the Legacy Virus, and the pivotal solution lies within the grasp of the Gamesmaster. Extending an opportunity to the X-Men, he proposes a game where they can claim the coveted remedy. Simultaneously, he extends the same proposition to their longstanding adversaries, with an extra incentive of obliterating the X-Men. Faced with this ultimatum, the X-Men are compelled to divide their forces in a quest to locate the cure before facing irrevocable demise.