A forensic psychiatrist decides to change work. Days before leaving, a case of 5 shot on a Copenhagen city bus might involve an old patient of his. Other murders follow. He can't stop before the case is solved.

Detective Katrine Ries Jensen and legal psychiatrist Thomas Schaeffer form a special unit at the Copenhagen Police investigating serial killings. A case from Schaeffer's past crops up. As a young psychologist, he held back from sending a patient, who was manically drawing the details of a traffic accident, to a secure hospital. Now these bloody scenes resurface.—Ermintrude