In Japan, scientifically advanced invaders from the war-destroyed planet Mysteroid cause an entire village to vanish, then send a giant robot out to storm the city by night, after which they request a small patch of land on Earth and the right to marry earthling women, claiming to be pacifists. Mankind must decide whether to capitulate or to resist.

The Earth is threatened by an alien race who kidnap and kill humans and even animals and use them for their body parts. In the year 1980 S.H.A.D.O. (Supreme Headquarters Alien Defence Organization), a highly secret military organization, is set up in the hope of defending the Earth from this alien threat. This organization operates from a secret location beneath the Harlington-Straker film studio in London. S.H.A.D.O. also has a base on the moon with Interceptors as well as an early warning satellite that detects inbound UFOs (called S.I.D.), and operate a fleet of submarines. General James Henderson and commander Ed Straker have a team of highly trained and well equipped females and males to battle the regularly incoming hostile UFOs.

From deep within the tomb of the Egyptian pharaoh Tutankhamun, Professor Douglas McCadden ships the coffin of Ankh-Vanharis to the California Institute of Sciences where X-rays reveal five diamond-like crystals hidden within the coffin. Technician Peter Sharpe steals the crystals but doesn't notice that the powerful X-ray has revived a green fungus. When the coffin is opened at a university press conference, the reporters uncover more than they bargained for. The mummy has disappeared... and the Time Walker is alive again!

Archaeologist Shum finds an antique jade with supernatural power in Greece. The stone is wanted both by KGB's agent Karoff and the Interpol. Shum asks his friend Nike for help. However, Shum is finally caught by KGB but the jade is slipped into the hands of a boy called Pan.