As Doc Terror's borg Mutron attempts to steal an experimental virus, the canister is accidentally damaged when the Centurions apprehend him. The Z-80 virus then begins spreading over the Earth. The only one able to stop the virus is its creator, Professor Manfred Owell, who left with other scientists twenty years ago to live inside a sungrazer comet under the leadership of Dr. Daimon Zemo, intending to create a utopia. Crystal and the Centurions use the Starfire, a prototype ion drive ship to get to the comet in time. Inside the comet, the Centurions meet up with Owell and Zemo, who distrusts them. As the comet is now on a course straight for the Sun, Owell requests the help of the Centurions to save the comet against Zemo's objections. As the virus spreads over the Earth, the Centurions must deal with Zemo's sabotage and save the comet as well as their homeworld.
Science Lesson: Genetic modification by Crystal.