Decepticon World universe

The Autobots' desperate attempt to launch the Ark ends in failure, and the majority of Iacon's inhabitants are permanently off-lined. Megatron reigns supreme over Cybertron, as well as many other worlds conquered by the Decepticons, now truly an Empire. The few survivors of the Ark Massacre live beneath the surface of the planet, determined to survive no matter the cost.

Optimus Prime is dead, killed by Megatron, and the Autobots are in hiding, literally underground. Bumblebee leads a ragtag group of survivors, preparing a last desperate surprise strike against the Decepticons.