After discovering ancient alien symbols that link to the Transformers, a timid Sam Witwicky (Shia LaBeouf) is suddenly thrust back into the primeval battle between the Autobots and Decepticons. Turning to his childhood friend, Mikaela Banes (Megan Fox), for help, Sam slowly begins to realize that he has always been meant for bigger things. Rediscovering his confidence and purpose, Sam must summon the courage to unravel the mystery of the symbols and stop the Decepticons from destroying mankind's existence.