Sven is willing to testify against Waaler, but he is adamant of his innocence of the murders, and consequently his testimony is wholly dependent on Hole exonerating him. Hole is faced with the daunting task of discovering the true murderer in a single day. However, a clue is provided by a seemingly irrelevant photograph which Sven shows Hole, and this combined with a very minute but precise piece of forensic evidence points to a completely unexpected perpetrator. Leaving Sven chained up, Hole encounters his new suspect in the immediate aftermath of his committing yet another murder. Hole comes very near to being killed himself, but eventually the killer commits suicide. Just as Hole believes that he is in the clear, Waaler calls to inform him that he has kidnapped his surrogate son Oleg and demands that he trade Sven for the boy.