The Autobots disperse as the colossal Scorponok lashes out at them, grabbing Arcee once Zarak determines that she holds the coveted key. Before the Autobots can respond, Zarak transforms Scorponok to battle station mode and leaves for Cybertron with the other Decepticons. Optimus Prime, fearing the consequences should Galvatron access the chamber, orders immediate pursuit, but Spike requests that he be left behind with Cerebros, a pacifistic Autobot whose desire to escape strife made him refuse to become a Headmaster. Optimus reluctantly acquiesces and takes off, leaving the human to start rebuilding the remains of a Hive city. Meanwhile, as Ultra Magnus and various Protectobots pin Galvatron in a crossfire, Scorponok arrives and the Decepticons easily beat the Autobots. Galvatron finds the marriage between cybernetics and organic life repellent, but he grudgingly consents to maintain internal rest as the Combaticons complete a rocket engine, designed to push Cybertron toward Earth and obliterate both worlds with plasma energy. Shortly after, Optimus's ship reaches Cybertron, but the Nebulans take off to destroy the key, lest the plasma energy reach Nebulos as well. However, as Vector Sigma has decreed that the key be kept safe, the Autobots follow Gort and the others into Scorponok to prevent them from harming it, but the Decepticons capture them all. As Galvatron delays opening the chamber long enough to ensure the Decepticons' escape, Spike pulls in to counter his enemies with the creation for which he and Cerebros form the core, the enormous Fortress Maximus. Defeating Scorponok, Spike detaches from the giant to rescue Daniel and the Autobots. Moments later, plasma energy surges through the planet, causing a nearby sun to go nova as a wave of it strikes Scorponok and sends him tumbling into the unknown with the Decepticons. Spike then shuts down the chamber and converts the rocket engine to save the sun by channeling its tremendous excess energy through Vector Sigma, reviving the planet and its inhabitants and thus bringing forth a new Golden Age.