1972. On a cold March morning the weekend peace is broken when a frantic young cyclist rings Inspector Kolbj rn 'K2' Kristiansen's doorbell, desperate to speak to the detective. K2 lets the boy inside, only to discover that he is being pursued by K2's colleagues in the Oslo police. A bloody knife found in the young man's pocket matches the stab wounds of a politician murdered just a few streets away. The evidence seems clearcut, the arrest couldn't be easier. But with the suspect's identity unknown, and the boy refusing to speak, K2 finds himself far from closing the case. And then there is the question that K2 can't get out of his head: why would a guilty man travel directly to a police detective from the scene of his own brutal crime?