In the present day, the Decepticon known as Blackout arrives in a U.S. military base in Qatar to find the location of Megatron and the AllSpark. He tries to hack into the files of the computer base, but is stopped by Captain William Lennox and his team. Back in the United States, Captain Witwicky's descendant Sam Witwicky buys his first car which turns out to be the Autobot scout Bumblebee and helps him woo his crush Mikaela Banes. Later, Sam catches a glimpse of Bumblebee's true form when he signals the other Autobots.
On Air Force One, another Decepticon named Frenzy infiltrates the plane and tries to hack into the network again, only this time is more successful until he is stopped by the US Security Defense before he can retrieve all of the file information. Frenzy is then picked up by his partner Barricade and they go after Sam after learning he has the glasses needed to find the AllSpark. Sam is rescued by Bumblebee and Mikaela also learns of the Transformers' existence. Bumblebee fights Barricade and manages to subdue him while Sam and Mikaela decapitate Frenzy, but he still survives.
Soon, it is up to Sam to decide Earth's fate. Optimus urges Sam to put the AllSpark in his chest, which will destroy them both, but Sam instead inserts the cube into Megatron's chest, which kills him and destroys the AllSpark. All of the dead Transformer bodies are dumped into the Mariana Trench at Atlantic Ocean to be hidden, Sector 7 gets closed down by the President of the United States, and the Witwicky family are released from custody.