"The Soil Biotron is one of the first places on earth where we can study both the above ground and below ground effect of carbon dioxide on trees.

In addition to Biotron, Rann's team of "Micronauts" includes Princess Mari of Homeworld, who, with her brother, Prince Argon, are the only survivors of the slaughtered royal family.

After several more encounters with beings such as Doctor Doom; the heroine Wasp and villain Arcade, Microtron and Nanotron sacrifice themselves to reanimate Biotron's consciousness in the Micronauts' new vessel.

Commander Arcturus Rann (returning from a thousand-year deep space voyage in suspended animation) and Biotron, his robot co-pilot, return on the HMS (Homeworld Micro Ship) Endeavor, to discover Karza has slain the royal family, who are in fact Rann's parents.