The Autobots led by Optimus Prime make a perilous last stand to hold off the Decepticons conquest of Cybertron. Outnumbered, outgunned, pushed to the brink of extinction. The battle-weary band of resistance fighters orchestrates a desperate series of counterstrikes on a mission that if somehow goes right, will lead to unthinkable choice: kill their planet in order to save it. It is a world where choices the characters make are constantly questioned, challenged and cast into doubt. The Transformers and everything we know about them are under siege.