While Henrik Bargen, a private investigator in Flensburg, reopens a double murder case from April 1945, an English maritime historian dies in a ship collision. Shortly after, two men are murdered in Glücksburg. There seems to be a connection between the deaths from the past and those of today, and soon Bargen and the criminal police are investigating together. The trails lead to Riga, Wismar, and all the way to northern Sweden. Dark forces confront Bargen with a violence that makes him doubt his own strength.