Sam Witwicky is caught in the war between two factions of alien robots, the Autobots and the Decepticons. Sam is having hallucinatory episodes of Cybertronian symbols, and is being hunted by the Decepticons under the orders of their long-trapped leader, The Fallen, who seeks to get revenge on Earth by finding and activating a machine that would provide the Decepticons with an energon source, destroying the Sun and all life on Earth in the process.