After a year of marriage, Marge Farrell grows despondent as her husband Bill Farrell becomes cold and distant, even toward their new dog, a surprise anniversary present. The dog barks and snarls at him, and one night he kills it in the basement, telling Marge the dog was strangled by its collar while pulling on its tethered leash. She also worries about not conceiving, despite various tests that suggest she can have children, and a doctor who suggests that Bill come in to be tested as well. Her doctor, Dr. Wayne, confirms she can have children and recommends that Bill undergo tests too.
She soon notices that other husbands in their social circle are behaving the same way. One night, she follows Bill to a secluded area in the woods, where she discovers that the man she married is not himself at all but an alien impostor. An extraterrestrial life form leaves Bill’s body shell and enters a hidden spaceship, revealing a broader, chilling invasion plan.
Marge tries to warn others, but too many men in town have already been taken over. She attempts to call Washington, D.C., but all outgoing lines are busy, and when she tries to leave by car, the exit bridge is reportedly down. Confronting Bill, she reveals that she knows he is an alien. Bill explains their ultimate plan: on his dead planet, females are extinct, so the males of his species are taking over Earth to breed with the women, with scientists aiming to modify bodies so the union can continue. Yet they did not anticipate that inhabiting human shells would awaken in them feelings like love, a sensation foreign to their race. One of the men even dies from a drowning accident only to be revived with oxygen, a sequence that underscores the perils of their partnership with human biology.
Finally, the doctor gathers a posse of men who cannot be disguised aliens because they have fathered children. They assault the aliens in their hidden spaceship, and bullets fail to pierce the invaders’ defenses—protected by a force field. The aliens prove vulnerable to two German Shepherd dogs used by the posse, and the attackers kill them one by one. Entering the ship, the posse finds all the human captives unconscious but alive, hooked up to apparatuses that allow the aliens to inhabit human shells. As the captives are disconnected, the aliens die one after another. Just before the Chief of Police’s alien occupant destroys his faux body, a warning is broadcast to the aliens in orbit that they have been discovered. A fleet of alien ships retreats from Earth space, leaving the humans to escape the doomed ship as it explodes. The operation frees the captives and reuniting Marge with Bill, who is still in his human form, at last marks a fragile, bittersweet victory for the people of their town. In the end, the story lingers on the resilience of a wife who refused to accept an invisible invasion, and the bond that endures even when a marriage is stretched to the limit.
Marge and Bill’s renewed reunion closes the tale with a quiet, hopeful note, even as the wider threat recedes into the shadows of space.
