It starts with just one body - the hands bound, the skin covered in marks.

Detective Superintendent Jeanette Kihlberg is determined to find out who is responsible, despite opposition from her superiors. When two more bodies are discovered, it becomes clear that she is hunting a serial killer.

With her career on the line, Kihlberg turns to psychotherapist Sofia Zetterlund. Together, they expose a chain of shocking events that began decades ago - but will it lead them to the murderer before someone else dies?