In an animated mid-1980s' Seattle, high school students Spike, Miko, and Raquel with Spike's Dad, encounter a group of cybernetic aliens called the Autobots led by Optimus Prime. They were forced to be exiled on Earth after their home planet, Cybertron, was ravaged by a surge of dark energon through the efforts of the vile Decepticon leader, Megatron. Eventually the Autobots are tracked down by their enemies, and the kids are caught into a covert war between the two alien factions. While a shadowy government agency named Sector Seven meddles in it.
Optimus Prime himself is captured by Sector Seven Agents with HIVE mercenaries and he is held captive in a mountain secret base. Before long Megatron reunites with his archenemy during a raid on the base. And they fight until an explosion sends them to the forests below. Optimus is heavily damaged and Megatron aims his gun at him. Autobots with the teens gang up on Megatron before Optimus gets up and shoots Megatron in the heart revealing a dark energon crystal within it. He reveals that with the power of Unicron, he will never die. Arcee tears the crystal from him and he falls to the ground. The Autobots send the body to Decepticons as an ultimatum to surrender or else face their wrath. The movie ends with the teens going back to School as Optimus reflects on the nature of humanity in his end movie monologue.
