Optimus Prime finds his home planet, Cybertron, now a dead planet, in which he comes to find he was responsible for killing. He finds a way to bring the planet back to life, but in order to do so, he needs to find an artifact, which is on Earth.

Two decades after the freak alien invasion that nearly destroyed mankind a new threat emerges. This Alien mothership is more than twice the size as the last one and once again, the world's armies must band together to save...