Through his Space Bridge, Megatron raises the dead Transformers of Cybertron, and summons them to Earth. The Autobots have to find a way to sabotage the Bridge, or else their new home will be destroyed by the legion of undead Decepticons.
The ultimate showdown unfolds in Earths orbit as the Decepticons, aided by Megatrons undead army, do battle with the Autobots with the fate of the Earth hanging in the balance.