Description
After a year of marriage, Marge Farrell (Gloria Talbott) is despondent that her husband Bill (Tom Tryon) is cold and not acting toward her the way he did before they were married. He doesn\'t show any signs of genuine affection towards her or toward his new dog, a surprise anniversary present from Marge. The dog barks and snarls at him whenever he approaches; he kills it in their basement, telling Marge the dog was strangled by his collar while pulling on his tethered leash. She is also becoming concerned because, wanting a family, she has not become pregnant. After undergoing various tests, her doctor assures her she can have children; he suggests that Bill come in and see him to be tested.
She soon notices that other husbands in their social circle are acting the same way. One night, she follows Bill when he goes out for a long walk. He heads to an isolated area in the woods, where she discovers that he is not the man she thought she married but an alien impostor. An extraterrestrial life form leaves Bill\'s body shell and then enters a hidden spaceship.
She confronts the alien Bill, and he eventually explains that all the females on his dead planet are extinct. He and the other males of his species are taking over human men so they can have offspring with Earth\'s women, saving their race from extinction. Marge is horrified at the prospect and tries to warn others of the alien plot, but too many men in town have already been taken over, including the town\'s Chief of Police, who does nothing after hearing her story. She attempts to call Washington, D.C., but all outgoing phone lines are busy. She attempts to leave by car and the local police stop her, saying the only exit bridge that leads out of town is down.
Finally, her doctor (Ken Lynch) comes to believe her wild story, and he gathers up a posse of men he knows cannot be disguised aliens. They attack the aliens in their hidden spaceship. Bullets can\'t hurt the invaders, who are surrounded by a force barrier. The aliens, however, prove to be defenseless against a pair of German Shepherd dogs being used by the posse. The aliens are killed when the dogs attack, all except the alien Bill.
Entering the spaceship, the posse finds that all the human male captives are unconscious but still alive, including Bill. The men are each hooked up to an apparatus that helps the aliens become their captors while living in faux human shells. The posse begins to disconnect the captives, which kills the aliens one-by-one. Shortly before his faux human body is destroyed, the alien occupying the Chief of Police broadcasts a warning to his people in orbit that they\'ve been discovered by the humans. Thereafter, a fleet of alien spaceships is seen leaving Earth space. They must seek out humanoid females elsewhere now that their breeding plan on Earth has been discovered.
