At the beginning of the movie, the Autobots and the military are planning a secret war against the Decepticons. As more and more Transformers resurface, people discover that these robots have a much longer history on Earth than they imagined. Some officials even speculate that it was the Autobots who brought the Decepticons, and propose driving the Autobots away. Optimus Prime doesn't want to leave Earth unprotected and at the mercy of the Decepticons, so he asks Sam for help, requesting him to be the spokesperson for the Autobots to persuade humans to let them stay. Sam refuses; he wants to go to college and live a normal life like everyone else. However, his wish doesn't come true because the fragment of the Allspark on him influences him through its primal energy, causing him to have various strange thoughts and hallucinations. Sam's refusal to be the spokesperson has serious consequences for himself, the Autobots, and the entire world - Megatron, the leader of the Decepticons, is resurrected, along with ancient demons from the history of the Transformers...