In the middle of the summer holidays, the body of a drowned man with ligature marks on his wrists is recovered from Tammerkoski. The investigation by Koskinen's team is further strained by the death of a dubious music manager and the mysterious Carl Friedrich.

Another body is found in Lake Näsijärvi, and the link between the victims begins to unravel. As Koskinen ponders the cases, he sets sail with his son Antti, and his instincts prove correct, but at the same time he unwittingly puts Antti in grave danger.

Frightening events are happening in the Kaleva Chinese Wall neighbourhood that go far beyond the normal petty squabbles and complaints of neighbours. Koskinen initially finds it difficult to determine whether it is a case of a pathological stalker, or a quietly smouldering danger, until a house-hunter who has been terrorising his neighbours is found murdered in his apartment.

As the investigation at the Chinese Wall progresses, the pool of potential suspects slowly begins to shrink until there are only a few left. The tragic suicide of a young girl gives Koskinen the missing piece of the puzzle, and a surprising picture is laid bare.

As Luttinen's sick leave continues, Koskinen must attend the examinations herself. Under Koskinen's leadership, the police are on the trail of a long-running series of crimes in which lonely men have begun to die or disappear all over Finland.

The police's net around the criminals is tightening. They find themselves surrounded in a remote villa outside Tampere and refuse to surrender. A tragic shoot-out between the ruthless criminals and the police ensues.

Protesters against the man-made island in Tampere face a surprising amount of resistance, and a frozen body is found in the courtyard of Härmälä church. The activists appear to be involved in a homicide in one way or another, but Koskinen finds it hard to believe they are guilty.

The police get to the source of the money behind the scenes of the man-made island construction project. At the same time, Koskinen discovers the missing piece to a thirty-year-old investigation into a homicide that was thought to be an accident. The mayor's twin brother is also reported missing.

On the stairs of Tampere City Hall, a cut-off human head is found in a glass jar. An organisation called the Brotherhood of the Republic threatens to detonate five bombs in Pirkanmaa and a curfew is declared in Tampere. Roine tracks down the terrorist group.