In *Transformers One*, the story begins on Cybertron, showcasing the planet’s advanced technology and societal structure. Initially, Cybertron is a place of peace, but tensions rise as different factions begin to clash. The film explores how Optimus Prime and Megatron, who were once allies, become bitter enemies. Megatron, disillusioned with the corruption in Cybertronian society, starts a rebellion that leads to the creation of the Decepticons. His transformation from a charismatic leader to a tyrant is a key part of the story.

Meanwhile, Optimus Prime emerges as the leader of the Autobots, advocating for peace and justice. The film highlights his journey from a noble warrior to a determined leader fighting to stop Megatron’s tyranny. As the conflict escalates, Cybertron is ravaged by war, forcing both factions to seek refuge elsewhere.

The climax of the film deals with the aftermath of the war and the decision of both Autobots and Decepticons to leave Cybertron. This migration leads them to Earth, setting up the events of the original *Transformers* series. The film delves into the personal journeys of key characters, their motivations, and the ideological differences that drive the conflict.