Optimus Prime, heroic leader of the benevolent Autobots, describes in a voice-over the shutdown of the Transformers' home world, Cybertron. It was destroyed by the malevolent Decepticon leader Megatron in his quest to get hold of the All Spark. The Autobots want to find the All Spark so they can use it to rebuild Cybertron and end the war between the Autobots and the Decepticons, while the Decepticons want to use it to obliterate the Autobots and take over the universe. Megatron had managed to locate the All Spark on Earth, but crash-landed in the Arctic Circle and froze in the ice. After stumbling upon his frozen body in 1897, explorer Captain Archibald Witwicky accidentally activated Megatron's navigational system and his eye glasses were imprinted with the coordinates of the All Spark's location, an incident that left him blind and mentally unstable. Sector 7, a secret government organization created by President Herbert Hoover, discovered the All Spark in the Colorado River and built the Hoover Dam around it to mask its energy emissions. The still-frozen Megatron was moved into this facility and was used to advance human technology through reverse engineering.
In the present day, a group of Decepticons composed of Blackout, Scorponok, Frenzy, Barricade, Starscream, Brawl and Bonecrusher, have landed on Earth and assumed the disguise of Earth vehicles. Blackout and Scorponok attack the U.S. SOCCENT forward operations base in Qatar and try to hack into the U.S. Military network to find the location of Megatron and the All Spark. Their mission is thwarted when the base staff cuts the network cable connections. While Blackout destroys the rest of the base, Scorponok pursues a small group of survivors, led by Captain William Lennox and Sergeant Robert Epps, who have photographic evidence of the robots. Scorponok is eventually repelled and hides in the sand after the humans manage to call air support and damage his tail. During this battle, the military discovers the only effective weapons against the Decepticons' armor are high-heat sabot rounds.