Cult sci-fi horror directed by Terence Fisher. People all over Britain are dying in mysterious circumstances. Pilot Jeff Nolan (Willard Parker) seeks shelter in a local pub and joins a group of survivors who at first believe they are under attack from a foreign adversary. Before long, however, they realise that the unknown forces are robots controlled by aliens. Nolan and the others must find a way to defeat them before they are all destroyed by the extraterrestrials.