Story continued from UNCANNY X-MEN #307.
The war-torn island nation of Genosha is suddenly encased within an energy barrier, cutting it off from the rest of the world, courtesy of Exodus. In an underground chamber, the Acolyte leader is facing the desperate Fabian Cortez, who is holding Luna hostage. Exodus seizes control of Cortez’s motor functions and forces him to hand the little girl over to him—then he blasts Cortez. He follows this up by lashing out against Crystal, Quicksilver, Scarlet Witch and Jean Gray—whom he considers traitors to the mutant cause—and announces they will die with the nation….
On the streets above, the X-Men are rescuing humans from the rebel mutants when the Avengers arrive. The two hero teams decide to put aside their differences to make common cause against Exodus and end the war. Storm and War Machine fly up to examine the energy barrier and Rhodey’s armor is short-circuited when he tries to crash through. Storm is able to save him from plunging to his death with the aid of Sersi. Suddenly, the X-Men are contacted telepathically by Professor X, asking them to come quickly and Captain America leads the Avengers by their side….
In the dungeon, Xavier’s party is engaged in combat with the Magistrate Elite, Cortez’s guards. As things look dark for them, the two hero teams arrive and drive off the guards with their superior firepower, and rush the concentration camp inmates to the surface for help. When Professor X hears that the team members who are part of Magneto’s family are missing, he worries for their safety—then Rogue is knocked from the sky by a force bolt….
Underground, Exodus takes credit for the attack on Rogue and when Quicksilver defies him, he speeds up the hero’s already quick metabolism to life-threatening levels—then relents….
Aboard the SHIELD Helicarrier, the Avengers group led by Black Widow learns that the energy barrier is slowly constricting….
Above, Exodus appears to the assembled Avengers and X-Men, accompanied by the now hypnotized members of Magneto’s family. He proclaims to all within earshot that he is Magneto’s true heir and will purge the land of human blood. He uses his psychic powers to amplify the rebels’ bloodlust, creating a near-riot. The heroes split into two human-mutant teams: one battles the mob and the Unforgiven while the other confront Exodus himself. The powerful villain is able to withstand the massed assault of his opponents, while collapsing the energy dome, crushing the tops of tall buildings. Exodus announces that the child Luna will be the first to die and raises her over his head…giving Xavier all the time he needs to launch a psionic attack stunning the villain, allowing Black Knight to pierce him with his neural sword and rescue the child. As they survey the carnage, Xavier denounces the mutant rebels for their acts of vengeance, demonstrating they are no better than their human oppressors. Exodus, recovering some of his strength, predicts he will be the ultimate victor and, as he flies off, blasts Quicksilver with an energy bolt. Black Knight performs CPR and revives him, and the parents and their child are reunited.
Epilogue: as Captain America and Professor X relax while waiting for relief to arrive, Jenny Ransome comes up and denounces Xavier as a hypocrite for concealing his own mutant status from the world. Xavier explains that he once thought it was necessary so he could act as a bridge between human and mutant but now he is not so sure….