Jack Arnold directs this sci-fi drama based on a short story by Ray Bradbury. Astronomer John Putnam (Richard Carlson) is intrigued when he observes what appears to be a meteor in the night skies of Arizona. However, when the object lands in the desert Putnam becomes convinced that it is no natural phenomenon. The locals are distrustful, seeing the astronomer as an eccentric intellectual, and refuse to listen to his theories. He then discovers that the UFO was in fact an alien spacecraft, whose occupants are now replacing the local community with exact doubles.