An armored car service has been attacked in Gothenburg, but the watchmen have no way to get in touch with HQ since the thieves used interfering transmitters, or jammers, to block all communication. While the local police begin their investigations, Johan Falk and his team delve into the background of the attack and suspect a group of ex-officers who served in Afghanistan. More surprising, however, is the role of a certain Seth, who has just been released from prison and has supplied the bank robbers with weapons. Johan wants Seth to work for the GSI as an informer. His first job looks like a perfect plan to rob a money transport, and there's even a "dry run" to make sure everything goes as planned. The team soon realizes, however, that it may have placed too much trust in Seth and that the rehearsal is really a deadly trap...