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.

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.

The media and the top management of the police demand results; Hautalehto secretly follows a different line of investigation; Hautalehto's budding love suffers from work obligations.

KRP and Hautalehto join forces to get to the bottom of what happened. Hautalehto underestimates the power of the killer's mad thirst for revenge and puts the innocent man in mortal danger.