Sam Witwicky leaves the Autobots behind for a normal life. But when his mind is filled with cryptic symbols, the Decepticons target him and he is dragged back into the Transformers' war.

When Sam Witwicky's first car turns out to be a shape-shifting alien robot, he becomes a key figure in a fight to save Earth from the evil Decepticons.

Former cop Brian O'Conner is called upon to bust a dangerous criminal and he recruits the help of a former childhood friend and street racer who has a chance to redeem himself.