Quick recap
Optimus's Team Prime hides in an old missile silo near Jasper, Nevada: Arcee, Bumblebee, Bulkhead and the medic Ratchet. When Starscream kills Cliffjumper, three teens, Jack, Miko and Raf, get pulled in and become Autobot allies, along with Agent Bill Fowler. Megatron returns from exile with Dark Energon, which can reanimate the dead, and tries to use a space bridge, which the Autobots take down. Knock Out and Airachnid turn up over the season. At the end, Unicron awakens in Earth's core and sets off natural disasters around the globe. Megatron allies with the Autobots, and Optimus uses the Matrix of Leadership to put Unicron back into stasis. The price is steep: Optimus loses his memory.

