When a successful architect gets murdered, Harjunpää, Onerva and a new and irritating colleague, Bingo, begin an investigation; the date of a law student who is running a love scam ends terribly.
The homicide unit discover the motive and identity of the architect's killer; Bingo fails to control himself and gets frustrated; Onerva has a budding affair; Harjunpää realises that he must find a solution to his father's situation.
Gang members from East Helsinki arrive at a grand youth party and open fire, killing a popular rapper from Espoo. Harjunpää and Onerva set out to locate the shooters.
The gang war between Espoo and East Helsinki heats up; Harjunpää and Onerva try to figure out the gang members' backgrounds and connections; Harjunpää worries that his daughter is spending time with the Espoo gang and Sebastian.
The police are baffled when they learn about an eccentric creeper who breaks into people's houses at night and lies next to them but doesn't commit any violence; Onerva informs Harjunpää that she wants to leave the force.
The police try to discover the identity and state of mind of the hijacker; the victims find it hard to cope with the anxiety and fear after the hijacker's visits; Onerva reflects on the difficult decisions she made in her relationships.
