Megatron plans to drill his way to Earth's core in hopes of getting large amounts of energy. The Autobots try to stop him and initiate their new plan to take control over Devastator. When both sides battle for controlling Devastator, though, it causes disaster.
 

Most of the Autobots lose their ability transform to robot mode after the Decepticons use a device on them. A handful of Autobots still capable of transforming are their only hope.