Mighty Orbots is traveling with a convoy of Galactic Council members heading for the planet Centrus. Suddenly a small spaceship buzzes the convoy and Mighty Orbots tries to stop it, but it's just too fast and maneuverable. Then, to everyone's surprise, Mighty Orbots is forced to separate. They bring in the pilot of the rogue spaceship and he turns out to be Drennan, a friend of Rondu's who used his mental powers to separate the Orbots as a joke.
Drennan shows Rondu plans for the Drennan Device, the ultimate defense system which uses bands of gravitational force to make any planet impenetrable. He wants Rondu to use it here to protect the Galactic Council, and Rondu is all for it although Rob is suspicious because of the game Drennan previously played with the Orbots. The Galactic Council meets and, sure enough, Drennan turns out to be an agent of Shadow, and his Drennan Device has drained the energy out of all of the defensive ships and left the planet defenseless. The Orbots form into Mighty Orbots, but Drennan again uses his mental powers to put a block on their combination abilities, this time permanently. The Orbots are taken prisoner. Umbra, meanwhile, has decided to bring the Shadow Star to the defenseless Centrus and complete its conquest.
The Orbots are able to escape from their prison, but try as they might, they simply can't combine. Rondu knows that he's the only one who can possibly reverse what Drennan has done, so while the Orbots attack the Shadow fleet as a diversion, Rondu beams onto Drennan's ship and challenges him. Drennan seems to have the upper hand, but Rondu digs down deep and finds the strength to win the battle, and releases the mental lock. Mighty Orbots is quickly formed and the Shadow fleet is destroyed. The Shadow Star comes into sensor range and Umbra, seeing that Mighty Orbots is there, retreats.