When police find a Swedish literary critic tortured to death in a janitor's closet at Newark International Airport, they realize that the murderer has made off with the victim’s ticket and boarded a flight to Stockholm, where he apparently slipped through customs.

With no clear motive in sight, Detectives Paul Hjelm and Kerstin Holm of Intercrime' s A-Unit take over the investigation. They learn that the method of torture used was not only a highly specialized means of extracting information—secretly developed during the Vietnam War—but also that it was the modus operandi of an allegedly deceased homicidal maniac known only as “the Kentucky Killer”. As additional victims turn up on Stockholm’s outskirts, the team finds itself coming up empty-handed. Hjelm and Holm fly to New York, hoping to discover both the killer’s identity and the source of his interest in Sweden. What they quickly learn is that bad blood always comes back around.