Years after "Transformers: Armada", Megatron awakens inside Unicron and finds himself intricately woven into Unicron’s Spark Chamber. Trapped, but connected to the vast, planet-sized menace, Megatron becomes the conduit to aid Unicron's return to full power. In horror, Optimus Prime realizes that Unicron has found Energon in abundance on planet Earth. As the Decepticons are battling and transporting vast amounts of Energon back to Unicron, the Autobots fight to stop them as they re-energize Unicorn one section at a time. As the different power areas of Unicron go online one-by-one, we get closer and closer to a fully powered Unicron. The clock is ticking…the countdown to extinction.