As Optimus returns to Earth to face the mysterious "evil" prophesied, the Bee Team must prevent Steeljaw's pack from teleporting that same threat to Earth.
Optimus returns with old friends and dire warnings of a Cybertronian invasion of Earth, and the Autobots must defend their old home and their new one. Steljaw offers assistance, but can he be trusted?
Starscream comes to Earth with Bounty Hunters in tow, searching for the Scavengers' Mini-Cons, who can confer on him the ultimate power he craves for his revenge. His quest leads him to the Bee Team, where he takes Bumblebee hostage.