During G-Biowar I (the first global biowar), a powerful new form of retrovirus was released as a deadly reprisal from the enemy. The viruses unleashed biological forces which couldn't be stopped, leaving the planet filled with new and deadly forms of life.

Only a few survivors remain in suspended animation in O.P. Odysseus, an orbiting platform circling Avalon. The space station's purpose is to keep the surviving humans alive until Avalon is habitable again. The crew of the Odysseus have been frozen in cryogenic tanks for hundreds of years, and now the onboard computer has awakened them.

Computer probes show that conditions on Avalon are hostile but livable. The question is; where can the crew of Odysseus set up a colony? The gameplay involves piloting an organic ship to Avalon, flying over areas which the probes have designated least hostile, ascertaining planetary conditions and, ultimately finding a new home for the remaining survivors.