The Autobots belive that the Decepticons were killed when their starship crashed into the ocean, however, the Decepticons have built the remains of their ship into an underwater headquarters and a "Space-bridge." The Autobots send Spike and Bumblebee out to track down Megatron, who needs a volunteer to drive the transport ship to Cybertron. Megatron brainwashes Bumblebee to trap The Autobots into a trap. The Decepticons leave the Autobots buried inside a cave, later they escape from the cave and arrives to the "Space-bridge." Bumblebee saves Spike (with the help of Optimus Prime) and the Autobots send Megatron to Cybertron.