The Gate of Hades is a doomsday device left unfinished by the UPDO After it was deemed a terrible weapon. The Androva repaired what was left to convert into a hunting post, then later after the Human-Androva War, used it as a Earth Base to defend in against humans. It was later destroyed after crash-landing on Earth 10,000 years into the past, and then after being rediscovered, blown up by Jack Morrison in the year 2009.