 Dave Lister, Arnold Rimmer, Kryten, and the Cat take a "Starbug" to investigate the wreckage of a ship called SSS "Esperanto" on an ocean-covered moon.The group discover that the ship was conducting marine seeding experiments that included accelerating the evolution of life on the planet, but find that all life onboard had committed suicide.Kryten discovers this was caused by mutated form of squid ink that contained a hallucinogenic nerve toxin, and that the suicides were caused by the toxin giving its victims severe depression, stating that he, Lister and Cat are now being affected by it.