Alan Nourse

On Jupiter's moon Ganymede, an alien life-form has taken over the body of a human astronaut, creating an almost perfect copy. It then begins the long return journey to Earth.

Out of the Unknown is a British television science fiction anthology drama series, produced by the BBC and broadcast on BBC2 in four series between 1965 and 1971. Each episode was a dramatisation of a science fiction short story; some were created for the series, but most were adaptations of already published stories. The first three years were exclusively science fiction, but that genre was abandoned in the final year in favour of horror and fantasy. A number of episodes were wiped during the early 1970s, as was standard procedure at the time.