the Decepticons, an evil race of alien robots, attack a U.S. military unit stationed in the Middle East. The men launch an immediate offensive—but meanwhile, back in the States, Secretary of Defense John Keller (Jon Voight) learns of a secret U.S. project involving Megatron (voiced by Hugo Weaving), a bad robot that crash-landed in the Arctic In the film's civilian side-story, teenager Sam (Shia LaBeouf) buys a used car, unaware it's an Autobot—a good robot. Neither does Sam realize that he has in his possession the key to the all-powerful cube—which all the robots, good and bad, desperately want. The film's many characters and plots collide with the help of the Autobots' courageous, red-and-blue-colored leader Optimus Prime (Peter Cullen).