[SHAD0] Supreme Headquarters, Alien Defence Organisation

Earth is being visited and attacked by aliens from a dying planet and humans are being covertly harvested for their organs by the aliens. A secret, high-technology international agency called SHADO (an acronym for Supreme Headquarters, Alien Defence Organisation) was established to defend Earth and humanity against the mysterious aliens and learn more about them, while at the same time keeping the threat of an alien invasion hidden from the public.