Two years after saving the world with the Autobots, Sam Witwicky is heading off to university when an ancient Decepticon named The Fallen returns to Earth seeking revenge. Their home planet of Cybertron rendered uninhabitable, the Autobots begin working with the military to hunt down any remaining Decepticons. Meanwhile, Sam and Mikaela race to unlock the secret history of the Transformers on Earth in order to save the planet from the most-formidable Decepticon to date.