The story is set in 2005, 20 years after the TV series' second season. After a Decepticon assault devastates Autobot City, Optimus Prime wins a deadly one-on-one duel with Megatron, but ultimately sustains fatal injuries in the encounter. With Megatron gravely injured, the Decepticons are forced to retreat, saving the Autobots. The Autobots are hunted across the galaxy by Unicron, a planet-sized Transformer intending to consume Cybertron and who transfigures Megatron to become the enslaved Galvatron.
