Sam Witwicky (Shia LaBeouf) gets drawn into a battle between two races of alien robots, one evil the Decepticons - and one good the Autobots. On a polar expedition at the beginning of the 20th century, Sams grandfather accidentally discovered the frozen body of the leader of the Decepticons, Megatron, who crashed on planet Earth hunting for the All Spark cube, a device that allows to create new robots which and the object of a centuries-long war between the Decepticons and the Autobots. Sams grandfather accidentally activates the robots navigation system, and the location of All Spark gets engraved into his glasses. The whole incident gets classified higher than top secret. To hide the location of All Spark, US president Hoover actually decides to build the Hoover dam around the cube, whose huge concrete structure serves to shield the cubes signals. Also, Megatron is shipped to the site, still in frozen state, and reverse-engineering its innards leads to the discover...