Building 31

A young man who disappeared during a Christmas party is the subject of a case for criminal inspector Antti Hautalehto at the police in Borgå. His boss's alcohol problem increases his work pressure.

Hautalehto investigates the strange drownings of a soccer team. An eyewitness flees for his life and Hautalehto's wife wants a divorce.

A new murder makes Hautalehto focus on the investigation; suspicions about a serial killer arise; Hautalehdo's love life takes a new turn.

The theory of a serial killer is confirmed by the statistics, but suspicions about them cause confusion in the investigation.

The police receive new information about drownings; the undertaker receives unexpected guests at the Christmas table and the Christmas dinner is fatally interrupted.

The Central Criminal Police is investigating the cases, and Hautalehto and the entire police force in Borgå are suspected of protecting their own.