Glenda Allen

The film resembles a Ten Little Indians plot, with the crew of a Western film in post-production (who are staying as guests on an island retreat) cropping up as corpses one by one after the mysterious and inexplicable kidnapping of a child. The film plays up its traditional mystery angle, with each of the guests being as likely a suspect as the next, in scenes such as one in which all of the guests sit around in the parlor and cast dramatic, accusatory glances at one another.

A physician discovers that two children are being kept virtually imprisoned in their house by their father. He investigates, and discovers a web of sex, incest and satanic possession.

Al Pereira arrives at the "House of Vice" and receives orders to stop spying on three women and a man, known as the Quadriumvirate, who deal in prostitution and drugs. When Lina Gordon hires him to find an envelope, Pereira discovers that Lina is in fact a man who has undergone an operation. Disgusted, he kills her.

Virginal nerd Jon Pigeon, manages to secure a job in a sex research institute where the patients run about the corridors naked, nude aerobics are encouraged and no man is safe from the crotch-grabbing tea lady. In his attempts to seduce pretty office secretary Cheryl, Pigeon invents a machine called Agnes that emits a 'sonic aphrodisiac' guaranteed to turn any man or woman into an slathering sex maniac. Although his attempts to zap Cheryl are singularly unsuccessful, Pigeon gets some interesting results when he accidentally turns the 'sex ray' on his bullying boss Nutbrown and the prudish Mary Watchtower.