On Cybertron, the Autobots, led by Optimus Prime, are on the verge of losing the Great Cybertronian War to their enemies, the Decepticons, had begin making preparations to leave the planet.

Bumblebee defends Sam and his girlfriend Mikaela Banes from the Decepticon Barricade, before the other Autobots arrive on Earth. They are searching for the Allspark, and the war on Earth heats up ...