Publisher's Synopsis
1960s British sci-fi thriller in which aliens from Jupiter's moon, Ganymede, come to Earth in search of females to mate with. Detective Hartley (Alfred Burke) is investigating the rapid increase in the number of missing women, while scientist Jack Costain (John Saxon) is looking into the rise in alien activity. It is some time, however, before they make a connection between the two. Will they be too late to put a stop to the creatures' plans?