GSI follow up a weapon trail that leads right into Kavkaz mafia headquarters on the west coast. GSI member Niklas Saxlid is the one in the group who is specialized in undercover operations, and he has penetrated Kavkaz' activities. But suddenly something happens and Niklas disappears.

Falk is blackmailed into smuggling a truckload of guns from Latvia.

Stockholm's coolest gang clash in a duel over who is the richest.

Five men break into Frank Wagner's apartment. Frank is able to escape and seeks out the help of Johan Falk. Has someone leaked that Frank is working with the police? Frank and John don't know who knows what and whom to trust.

When Johan Falk was 19 years old he lost his girlfriend Maria and their unborn child when Maria got hit by a car. Falk takes the accident very hard and do not even go to the funeral. He decides that crime must be fought and applies immediately to the Police Academy. The movies are, however, only about Falk as an police officer with many years of experience from the National Task Force. He often goes his own way and does not shy away from using controversial methods. This leads to that the colleagues often experience difficulties in cooperating with him and managers are forced to turn a blind eye to what he's doing.