A man visits his girlfriend in Amsterdam after the war. He soon finds himself, for inexplicable reasons, in a country house where two women as 'white slaves' have to learn all kinds of erotic skills, and where a private detective, who has sold his own wife to an Arab in Tangier, comes to investigate.

Detectives Grijpstra and De Gier are sent to investigate the case of a man who apparently hanged himself in a center for oriental meditation. It is ruled as suicide and the case seems to be closed, but the same night there is an attempted break in. The investigation hits a dead end and everyone involved is a suspect. Based on the book "The Corpse in the Haarlemmer Houttuinen” by Jan-Willem van de Wetering.

An Englishman in Holland gets involved in a murder case. It looks bad for him, but the wily Inspector Van Der Valk isn't convinced of his guilt.