Set up as the fall guy in a string of slasher murders, Boone decides he'll hide by crossing the threshold that separates "us" from "them" and sneak into the forbidden subterranean realm of Midian.

Many years after a nuclear war, the human survivors have created a new society where much of the work done by androids, referred to derisively by humans as "clickers". A police official who is concerned that his sister has become involved with an android is sent to investigate a larger rumor that the androids are developing reason and emotion.

Eight American soldiers, commanded by Lt. Eason, are chosen to infiltrate the Ploesti oil field in order to set signal fires to guide Allied bombers to Germany's most closely guarded target of the war. When landing in Roumania, they are supposed to be met by a partisan as their guide, but he has been killed by an Allied air-raid, and they are met instead by his daughter Nitza, who is very hostile to the Americans as she blames them for the death of her father. As they make their way to the oil field, Nitza and Manjack fall in love. He is killed in a skirmish with German troops and, as a dying wish, asks Nitza to continue with the group and help them with their mission. She does, the signal fires are set and Ploesti is destroyed.