It is night. A police car pulls over near a van with a flat tire on a desolate highway, where two young men are changing the tire. The police officers step out of the patrol car and offer their help. Suddenly, a third person gets out of the van. One of the officers reacts instantly - this man is a well known criminal, he understands he is recognized. He has also robbed a military camp ten minutes ago, and the van is loaded with explosives and assault rifles. The situation is tense. Later on, the two police officers are found shot dead in a way that looks like an execution. Martin Beck is working on the case and gets all resources he needs to get the unknown murderers. A hunt that gets complicated, because Martin's partner, Gunvald Larsson, was a close friend to one of the killed police officers and he is literally ready to use any methods to find the killer...