For centuries, Apocalypse tested the mutants of Earth to guarantee that only the strong would survive. Now, as he takes his throne on Arakko, another must rise in his place and ensure the mutants of Earth do not grow weak in his absence! Twelve mutants chosen from among the X-Men's greatest heroes - and villains - will compete for the honor, but only one can become the Heir of Apocalypse! Among them stand Cable, Exodus, Emma Frost, Forge, Mirage and Wolverine - but when a thirteenth contender crashes the tournament, endangering the lives of thousands in the process, will any survive to carry on in Apocalypse's footsteps? Not if Mister Sinister has anything to say about it! Meanwhile, Archangel takes it upon himself to make sure no one else suffers at the hands of En Sabah Nur!