Kepler, Lars

Late one night, outside Stockholm, an emaciated young man named Mikael is found wandering. Thirteen years earlier, he went missing along with his younger sister. They were long thought to have been victims of Sweden's most notorious serial killer, Jurek Walter, currently serving a life sentence in a maximum-security psychiatric hospital. Now Mikael tells the police that his sister is still alive and being held by someone he knows only as the Sandman.

Follows Detective Joona Linna's investigation into two murder cases in Stockholm that have been staged to look accidental, scenes that prompt Joona to discern a link between the crimes and a more sinister operation.

Detective inspector Joona Linna investigates a triple homicide in Tumba, Sweden, where the only surviving witness is the young boy who watched his family get killed, and in an effort to obtain information from him, Linna seeks out Dr. Erik Maria Bark to hypnotize the boy, an act which Bark had vowed never to do again, which reveals a unsettling chain of events.