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.
A rich Frisian farmer has been murdered in Amsterdam and police duo Grijpstra & De Gier are sent to investigate. Adjutant Grijpstra has problems at home again and is happy to leave for Friesland to investigate the murder. Sgt. De Gier finds the Frisian Hylke much more interesting than the murder case. In Leeuwarden there is a real Chinese war and a brutal robbery at the cattle market. Suddenly there is that friendly rattling, asthmatic rat who provides an unexpected solution.
The wealthy Hamburg gallery owner Elaine Troost dies mysteriously on a stormy fall night and her body is subsequently found in the bathtub by her daughter Gabrielle. The autopsy of the body reveals that her death was caused by violence. A witness testifies shortly afterwards that she saw the art forger Jan Vleuten outside the gallery owner's house on the night of the murder. He is nicknamed "the blonde monkey" because of his strange fondness for primates and his light blonde hair...
