The Endless Desert The episode is set in the central desert of Texas, 200 million years into the future. At this point in the future, there are no mammals, birds, reptiles or amphibians, as they were all wiped out by the mass extinction. The episode focuses on four species: (1) Terabyte, descendants of termites that live in massive air-conditioned underground cities and farm algae; (2) Gardenworm, a descendant of the Convoluta worms that house green algae in fleshy lobes on their back that convert sunlight into food for it; (3) Slickribbon, a transparent worm with pincer jaws and a nasty sting; (4) Gloomworm, a simple worm that is descended from a single type of bristleworm that survived the mass extinction. With no rainfall reaching the middle of the single continent, water is scarce and many animals live in underground lakes and caves to get away from the heat of the desert.