The inhabitants of Ganymede need to find mates from another world or they will become extinct. They soon discover a suitable breeding stock amongst the females of planet Earth.

Top Cast

John SaxonDr. Jack Costain

Patricia HainesAnn Barlow

Alfred BurkeDetective Supt. Hartley

Maurice DenhamDr. Morley

John CarsonThe Major

Ballard BerkeleyCmdr. Savage

Stanley MeadowsDet. Tom Grant

Barbara FrenchJoyce Malone