Johan Falk's stepdaughter Nina has gotten in contact with her biological father, Orjan, discovering that he is in debt to an Estonian construction company in Gothenburg, leading to Nina's kidnapping.
It's been two years since John Falk and Frank Wagner broke their cooperation and Frank started working undercover with the police. Frank's search for Kevin crosses Johan's investigation and opens up a new collaboration between them - with the big difference that this time it's personal for Frank.
In Knohult things havn't changed much. Eulalia is tired of Nisse who's engaged in all sorts of inventions in his workshop or poaching in the forest rather than to repair the water pump. When Eulalia in protest begins swimming in soft drinks and water the plants with spirit Åsa-Nisse sees nothing...
GSI second in command, Sophie Nordh, flips gangster leader Seth Rydell and convinces him to infiltrate a rogue military group. For the first time GSI Chief Patrick Agrell realizes that he is using a ruthless psychopath as an infiltrator. Can Seth be trusted or does he have his own agenda?