Drathro was created in the Andromeda Galaxy and placed as guardian over the Sleepers in the underground Marb Station (part of UK Habitat) on Ravalox (i.e. Earth) until c. 2,000,000. He used the five hundred humans residing there, whom he called "work units", to keep the Sleepers alive and he used two humans, Tandrell and Humker, as his personal assistants. The station and he were powered by a black light converter on the surface. He also used an L1 robot and a train guard named Merdeen, who helped humans to escape to the surface without Drathro knowing.