Earth is attacked by the Legion, an alien race whose nanomachine-based composition allows them to quickly recover from any injury. Realizing the threat at hand, the Autobots and Decepticons join forces, working with the humans to repel the invaders, but a massive EMP takes all the Transformers offline, leaving the humans to be quickly overwhelmed. Seventy years later, civilization is in ruins and humanity is on the brink of extinction. However, a small resistance force known as the Renegades continue to fight back, and have begun to recover and revive the derelict Transformers in the hopes they can help finally turn the tide of the war. With Optimus Prime and Megatron both missing in action, the recently reactivated Bumblebee steps up to lead the survivors in a final campaign that will decide the fate of the planet.
