1970. Inspector Kolbjørn Kristiansen, known as K2, witnesses a young woman desperately trying to board a train only to have the doors close before her face. The next time he sees her, she is dead. As K2 investigates, with the help of his precocious young assistant Patricia, he discovers that the story behind Marie Morgenstierne's murder really began two years ago, when a group of politically active young people set out on a walking tour in the mountains. There, one night, the party's charismatic leader—and Marie's boyfriend—Falko Reinhardt vanished without a trace. But were the relationships within this group all they appeared to be? What did Marie see, that made her run for her life that day? Could both mysteries be linked to Falko's research into a cell of Norwegian Nazis? It soon becomes clear that Marie's death will act as a catalyst in a dark set of events which will leave K2 and Patricia confronting their most dangerous and explosive investigation yet.