Tumbleweed

Detectives Gripstra and De Gier, those ornaments of the Amsterdam police force, are still carrying on under the command of their superior officer, the commissaris. They are assigned to investigate the murder of Maria van Buren, a high-class prostitute living in a houseboat on the canal, who has been stabbed in the back. The three men who have been enjoying her favors produce apparently unshakable alibis. Investigation of other visitors yields no clues but examination of the houseboat leads the detectives to suspect that Maria may have been dabbling in sorcery. In pursuit of this clue, the cammissaris flies to Curacao, where Maria was born and where her father still lives. Delving into the past, he uncovers evidence that seems to point to an unforeseen conclusion. In the meantime Gripstra and De Gier, following a hunch that leads them to another island - a cold, wet island off the coast of Holland - uncover evidence pointing to the same conclusion. From then on, events moved quickly. There is a wild chase at sea but the detectives have to call in the Air Force before they get their man, and even that is not the end of the affair. --- from book's back cover