Twenty years after their arrival on Earth, the Visitors have deeply entrenched themselves on the planet, enslaving the human race turning them into followers. The Resistance is losing the war with their alien masters until they gain a powerful and mysterious new ally.
The scenes in this film featuring Doris Day and her young on-screen son had a special emotional resonance for Day, since in real life she had often had to leave her own pre-school-aged son Terry behind with his grandmother while touring as a big band singer in the 1940s. The set for Gary Mitchells' apartment is made up using sections of the apartment from "Rope" (1949)