During a police intervention, a macabre discovery is made in the trunk of a car. Josef and Oskar find themselves in the line of fire of a seemingly cold-blooded killer. But things are not what they seem.

The successful detective writer, Erica Falck, is thinking that her next book should be based on a true mysterious event from her childhood. When she was only 13 years old one of her dear friends and classmate Peter boarded a bus and then disappeared. Erica has been unable to let go of the tragic event and her first meeting with a real mystery. As she starts digging deeper into what really happened to Peter it seems as if she has awakened a sleeping beast. When Erica's only connection to Peter, his brother Ivan, who is on his way to see her, gets stabbed and murdered her mission becomes not only to solve the mystery about Peter but also to find out who killed Ivan. During a high school reunion party the heat builds up when Tina, Peter and Ivan's enigmatic sister, unexpectedly shows up and later at the party another murder is committed that leads Erica closer to the truth about what actually happened to the missing Peter.

December 1942. Two young soldiers leave their posts at checkpoint 83 in North Värmland, Sweden and make their way through the ice cold winter night towards the Nazi-occupied Norwegian border. Sweden stands on the brink of invasion and they want to see the enemy everybody's talking about. But the adventure ends in disaster and soon thereafter Lieutenant Aron Stenström finds out that his brother Sven is one of the missing soldiers. With the odds stacked against him he is forced to go behind enemy lines on a secret rescue mission. Deep inside the Norwegian forests Aron realizes that a completely different kind of line must be crossed if they're to come out alive.