Icelandic crime drama. An ex-drug dealer is found murdered in the old harbour area of Reykjavik following a brutal attack.

Detective Arnar Bodvarsson arrives from Oslo to help Kata find a link between the two victims. At the memorial to the latest victim, they catch the prime suspect, who has broken into his father's office.

An elderly lady is found murdered at an abandoned boys' home, and her body has similar wounds to those found in the previous two killings. Kata and Arnar are under pressure to identify and capture the killer.

Kata, Arnur and the Reykjavik team examine boxes of documents from an inquiry into Icelandic children's homes in an effort to identify both the next possible victim and the killer.

The team make advances in identifying a suspect with the help of a fingerprint lifted from Thor's photograph and CCTV footage from the shopping mall, but their success is jeopardised by a leak to social media that risks putting further lives in danger.

Kata is suspended from duty for losing her gun. Arnur questions the hospitalised Steinthor, who fervently denies killing his friend Tomas. Meanwhile, Kata gets an intriguing phone call from Hakon, who has discovered something in the basement at Valhalla.

Kata and Hakon continue their investigation in Borgarnes, where the chief of police at the time of Tomas’s disappearance admits mistakes were made. Back in Reykjavik, Arnar discovers he has missed two telephone calls from Fannar Thorsson.

Hakon calls from Borgarnes, furious that Kata did not tell him that she had escalated the referral about the Valhalla investigation. Unperturbed, Kata is determined to find justice for the victims.