Inger Johanne Vik, a psychologist and former FBI profiler, and her autistic daughter Stina are entangled in an investigation into a string of horrific and unsettling deaths that occurred in Stockholm.
Ingvar goes to Uppsala to investigate the murder of Bishop Elisabeth Lindgren on Christmas Eve.
After much hesitation, Inger agrees to join the investigation. At the same time, she is now trying to understand the information from her daughters
Carlson is brought in for questioning after Inger Johanne reveals a personal relationship between her and Carlson.
Ingvar reveals a lead that seems to support her theory about the motive behind the murders.
The noose tightens around Marcus Ståhl, who has ended up in a precarious position.
Inger Johanne gets closer to the killer but then receives a very disturbing letter at her home.
Stina makes a decision that puts her and her sister in danger.