Steven Lang's plan to annihilate the mutant race are underway, as the X-Men battle his new generation of sentinels based on Dr. Trask's designs, and made to impersonate the original X-Men. But when Wolverine discovers the truth behind the X-Men attacking them, they quickly regroup.Meanwhile, Cyclops and Lang's other captives fight for their freedom against a madman bent on genocide. But when it comes for the X-Men and the prisoners to make their escape, the damage done by the sentinels to their shuttle is too severe. And with the massive cosmic flare approaching, no human could possibly pilot the shuttle safely to Earth. But could a mutant?