The series begins when Optimus and his crew, after picking up a disillusioned ninja named Prowl, are sent to clear rubble from a space bridge passage. There, the Autobots stumbled upon the Allspark and are immediately attacked by Megatron's battlecruiser, the "Nemesis". Through treachery by Megatron's second-in-command, Starscream, Megatron was fragged and the Autobots crashed on Earth in the early 21st century. After being in stasis under Lake Erie for 50 years, the Autobots awaken in Detroit of the near future, where they immediately discovered humans in need and became heroes of the city after stopping a Sumdac Industries experiment gone wrong. During the battle for the possession of the Allspark, Optimus goes offline after defeating Starscream, only to be revived by Sari Sumdac and her Allspark-infused key.