Deciding that Mighty Orbots is too powerful for his agents to defeat, Umbra has his agent Metanllis, who has the power to control minds, lure them to the planet Evilon with a stolen defense satellite.
SHADOW creates a robot named Tobor who is a dead ringer for the Mighty Orbots in their giant robot form. Framed for crimes committed by Tobor, the Orbots are sentenced to prison on Devil's Asteroid. The sadistic warden may also be an agent of SHADOW. The Orbots need to escape Devil's Asteroid and clear their name with the help of Rob and Ono.
When a space passenger liner is captured by pirates, Bort, feeling guilty and incompetent with earlier inadvertently endangering that particular ship, is the key to rescuing it.
Umbra revives a dead cyborg scientist to attack Earth with a bizarre mutagen that makes every mechanical device struck go berserk, while sickening Ohno.
On the watery planet of Reilos, the mining operations of valuable Aquarius ore are being disrupted by the attacks of Leviathan, a monstrous whale-creature over a kilometer in length. Mighty Orbots is dispatched to investigate.
The Orbots get their chance for fame when the Cosmic Circus arrives on Earth and the Orbots are sent undercover to sniff out suspected Shadow activity.
Transporting a dangerous Protean pod to Urbanos the most densely populated planet in the galaxy, Crunch's brainless actions allow the pod to be stolen by two local thieves "Kleptos and The Kid".
Fearing that Rob will shortly replace them on their birthday, the Orbots desperately attempt to prove themselves by invading Umbra's domain on their own when the villain threatens Earth's Sun.
