A computer virus has been attached to the Tampere tramway control. Virus messes up the entire test-phase operation of the tramway and causes a power outage.
As if Koskinen wasn't busy enough, a nightmare scenario takes place in the Hervanta area, Tampere: a 16-year-old girl is found strangled with a fishing line.
Koskinen's former colleague Roine has been admitted to a mental hospital. When the patients start to die of strange heart attacks, the old criminal investigator's suspicions are aroused.
The Violent Crimes Department is put in a tough spot when an unknown body turns up in the west side of Tampere. He had no chance of escaping the attacker because he was in a wheelchair.
A peculiar gang of disabled men have made the assisted living centre their home. Soon another attack takes place and a terminally ill woman, has no chance to escape from the killer's clutches.
An old man is beaten within an inch of his life in the Nekala area of Tampere and arson takes place in Hervanta. The main suspects are a teen gang. Soon one of the gang members turns up dead.
Chief inspector Koskinen and his team start investigating this senseless series of crimes. It is not an easy assignment, and it also causes distress in the youth caught up in the situation.