The soldiers of the Empire of the Hundred Demons steal a shipment of uranium with which they build a hydrogen bomb. Ryo and Hayato capture the leader of the handful of soldiers who reveals the truth: the bomb will explode under the command of the Demon Robot, endangering the life of the population in front of the laboratory area. The Demon gets the Getta ray collector in exchange but Ryo and Hayato penetrate inside the Demon Robot, foiling the enemy's plan. However, the robot still tries to blow up the bomb but the Robot Thrower destroys it before disaster can happen.