A romantic midnight swim leaves a man unconscious and his wife missing, presumed drowned. Van der Valk suspects that more than amorous intentions were at play that night, and he sets out to prove it.
When a dead man turns up on the deck of a canal barge, everyone is ready to dismiss him as a nonentity. The commissaris disagrees. Before Van der Valk can find out what happened to the man, though, he first must discover his identity.
Arlette's intuition proves truer than her husband's after a young woman is threatened in the park. Van der Valk tries to atone for his mistake by hounding the prominent Amsterdam buisnessman, but his personal feelings might be clouding his judgment.
While working on a case, a private detective is stabbed to death in a seedy apartment. Who was he watching for two weeks in the building opposite? And how did it lead to his death?
A rich, middle-aged American flies into Amsterdam to meet her young lover, only to learn that he has disappeared. While she worries about the safety of the missing man, Van der Valk fears that she is in danger herself.
An explosion almost kills a worker at a tractor factory, and a poor immigrant barber is bludgeoned to death in a luxury apartment that he shouldn't have been able to afford. Van der Valk looks for a link between the two apparently unrelated crimes.
Van der Valk searches for a teenage girl abducted on her way to a clandestine rendezvous with a married man. The man is ready to help in any way he can, but the commissaris finds her hotel-tycoon brother more willing to cooperate with the kidnappers than the police.
