When his dimension vortex fails to return Thor to Earth, he ends up on an alien world that has been marked for destruction by the Celestials. He now finds himself in combat with Arishem the Celestial Judge. Does Thor have the power to stop him? And what will he do when the true threat finally arrives? Meanwhile, in Asgard, the serpent god, Set, sends assassins to kill King Balder, beginning the countdown to the war of the gods!