Though they succeeded, Optimus was left with amnesia and believed himself to be his former self "Orion Pax". However the god of chaos Unicron emerged and threatened Earth, forcing the Autobots and Megatron to team up, and stop Unicron. Nearing the end of the season, Starscream goes rogue. Jack's friend Sierra also also makes certain appearances in the show. New characters include Autobot's Wheeljack (a minor character) and the deceased Tailgate as well as the Decepticons Knock Out, Breakdown, Airachnid and the deceased Makeshift and Skyquake. In addition, the Autobots must contend with MECH lead by Silas who are obsessed with obtaining the Autobot's technologies which leads to Jack's mom discovering their existence too. However Megatron was soon revived and took back command on his mission to find Energon and powerful weapons across the world. The Autobots were forced to deal with Starscream's schemes to stop the Autobots which lead to many near death experiences. The Autobots succeeded in stopping Megatron's plan to bring an army of zombies from Cybertron with a vile power known as Dark Energon, leaving Starscream in command in his absence. Along the way the autobots government liaison Agent Fowler also helps to keep there secret from the outside world. On top of that three human kids have discovered their existence and are now under their protection. Though the Decepticons vanished for three years, the death of Cliffjumper has signaled their return.
After the Great Exodus of Cybertron Team Prime lives on Earth in an abandoned missile silo in an alliance with the United States government as Earth's defense team against the Decepticons.