Transformers

The planet Cybertron was ravaged by a civil war between the two Transformer factions, the Autobots led by Optimus Prime and the Decepticons led by Megatron, for the AllSpark, a cube-like object that is the source of all Cybertronian life. The Autobots want to find the AllSpark so they can use it to rebuild Cybertron and end the war, while the Decepticons want to use it to conquer the universe. Megatron found the AllSpark on Earth but crash-landed in the Arctic Circle and was frozen in the ice. Captain Archibald Witwicky and his crew of explorers stumbled upon Megatron in 1897. Captain Witwicky accidentally activated Megatron's navigational system, causing his eyeglasses to be imprinted with the coordinates of the AllSpark's location. Sector 7, a secret U.S. government organization, discovered the AllSpark in the Colorado River and built the Hoover Dam around it to mask its energy emissions. The still-frozen Megatron was moved into the facility and was reverse engineered to advance human technology.

In the present day, the Decepticons—Blackout, Scorponok, Frenzy, Barricade, Starscream, Bonecrusher, and Brawl—have landed on Earth and assumed the disguise of Earth vehicles. Blackout and Scorponok attack the U.S. SOCCENT military base in Qatar and try to hack into the U.S. military network to find the location of Megatron and the AllSpark. Their mission is thwarted when the base staff severs the network cable connections. While Blackout destroys the rest of the base, Captain Lennox, Sergeant Epps, and their small group of survivors with photographic evidence of the robots escape the destruction, only to be pursued by Scorponok, but he is eventually repelled by air strikes. Lennox's team discovers that the only effective weapons against the Transformers' armor are high-heat sabot rounds. After Blackout's failure, Frenzy infiltrates Air Force One to hack into the military network and, in doing so, plants a virus. He finds the map imprinted on Captain Witwicky's glasses, which is owned by his descendant, Sam Witwicky. Frenzy and Barricade begin tracking Sam's location in Los Angeles.

One of the Autobots, Bumblebee, is also on Earth, disguised as a 1976 Chevrolet Camaro, and is bought by Sam while shopping for his first car. Bumblebee helps him woo his crush, Mikaela Banes. Bumblebee leaves at night to transmit a homing beacon to the Autobots, and Sam sees him in robot mode. Barricade confronts Sam and demands Archibald's spectacles, but Bumblebee rescues him and Mikaela. After Bumblebee upgrades his vehicle form by scanning a 2007 Chevrolet Camaro, they rendezvous with the Autobots: Optimus Prime, Jazz, Ironhide, and Ratchet—who have landed on Earth and taken on forms of Earth vehicles as well. Sam, Mikaela, and the Autobots return to Sam's home and obtain the glasses. Soon, agents from Sector 7, led by Seymour Simmons, arrive to arrest Sam and Mikaela, and they capture Bumblebee.

Frenzy, disguised as a mobile phone, secretly accompanies the group to the Hoover Dam and releases Megatron. Locating the AllSpark, Frenzy alerts the other Decepticons. Sam convinces the Sector 7 agents to release Bumblebee so that he can get the AllSpark to Optimus Prime. Frenzy's virus has shut down worldwide communications, but a pair of hackers, Maggie Madsen and Glen Whitmann, manage to establish a signal to the Air Force. The Autobot-human convoy goes to Mission City to obtain a radio that will guide the Air Force and secure an extraction for the AllSpark as the Decepticon forces attack the convoy. During the ensuing battle, Brawl, Bonecrusher, Frenzy, Jazz, and Blackout are all killed. Sam manages to ram the AllSpark into Megatron's chest, killing him and destroying the AllSpark. Optimus takes a fragment of the AllSpark from Megatron's corpse but realizes that with its destruction, their homeworld Cybertron cannot be restored. The government decommissions Sector 7 and dumps the corpses of the defeated Decepticons into the Laurentian Abyss. Sam and Mikaela begin a relationship, and Optimus sends a signal to other surviving Autobots, directing them to Earth.