An epic battle left a great city torn, but with the world saved. As humanity picks up the pieces, a shadowy group reveals itself in an attempt to control the direction of history… while an ancient, powerful new menace sets Earth in its crosshairs. With help from a new cast of humans, Optimus Prime and the Autobots rise to meet their most fearsome challenge yet as they are swept up in a war of good and evil, ultimately leading to a climactic battle across the world.