Sheppard, Daniel and a whole host of human and alien allies must contend with a growing conflict against an expansionist and militant regime of humanoid reptilians, as well as a conspiracy on Earth and an even more dangerous, ancient threat from the far reaches of the galaxy that will finally make its presence known right upon Earth's doorstep.

It has been nine years since life was restored to Cybertron. A Decepticon warlord appears on Earth intending to negotiate peace with the Autobots. Jack Darby finds himself with conflicted loyalties, while Wheeljack seizes upon a chance to get back in action, only for things to spiral out of control. Differing ideologies will collide, with serious consequences.