Ultra Magnus takes control of the Autobots, sending the dragon to the Arctic and fighting Megatron. Meanwhile, as Optimus fades, he struggles to identify a new Prime.
Mixing Dark Energon with Knock Out's refined Synthetic Energon formula causes Cylas to develop vampiric capabilities, and soon Knock Out and Starscream find themselves in the middle of a vampire-zombie-robot epidemic aboard the Decepticon ship.
The Autobots and Decepticons race to find the Omega Lock which can restore life to their home planet of Cybertron. The Autobots have to use every lethal weapon in their possession to stop Megatron and his troops from reformatting their planet into their evil image.
Ratchet agrees to perfect the Synthetic Energon formula, but then begins to sabotage Decepticon plans. Meanwhile, the Autobots use Laserbeak's tracker to find the warship.
The Autobots are on the run after the destruction of their base. Meanwhile, military strikes against the new Decepticon fortress, Darkmount, prove ineffective.