The R.U. Sirius is a space station orbiting the planet Earth. Disguised as a research outpost, its secret purpose is to intercept aliens before they reach the planet, thus preventing the average Earthling from finding out about the existence of extraterrestrial life.
The station was founded by the mysterious government agent known as Agent X and is monitored by the Department of the Paranormal. It mostly acts as an embassy to interact with alien species of all kinds; to welcome the friendly races and battle against hostile ones.
The R.U. Sirius is equipped with a biosphere containing several species, including prehistoric dinosaurs which were either cloned by resident (mad) scientist Dr. Melvin Practice, or brought onboard by means of his time machine.