Sheena's white parents are killed while on Safari. She is raised by the mystical witch woman of an African tribe. When her foster mother is framed for the murder of a political leader, Sheena and a newsman, Vic Casey are forced to flee while pursued by the mercenaries hired by the real killer, who hopes to assume power. Sheena's ability to talk to the animals and knowledge of jungle lore give them a chance against the high tech weapons of the mercenaries.
A space shuttle mission investigating Halley's Comet brings back a malevolent race of space vampires who transform most of London's population into zombies. The only survivor of the expedition and British authorities attempt to capture a mysterious but beautiful alien woman who appears responsible.