On a colonial supply base on Figaro Xll, Doctor Trudo's experiment (477/B12) goes wrong when the base's particle accelerator shows an energy spike and looks like exploding. Before Trudo can shut it down, a new atomic particle breaks free from the machine and forces Trudo to do its bidding... On a hillside away from the base, a Dronebot (with the glowy-light in his head) looks on, marking the day the Time Lords waged war against the Atomon!