Detective Peter Wendel's Cold Case Unit is understaffed and distracted: Jorma has quit, Caijsa's maternity leave looms, and Peter isn't doing well after accepting his brother's suicide; everything changes when a colleague is killed.

Peter and Barbro tail police commissioner Ludvig Larsson and find out something shocking.; Caijsa and Jorma try to discover why Conny had the old case files and learn that one of them is missing: the investigation into Urban's suicide.

Peter wants to keep Vera away from the police commissioner, while Veronica wants Peter off the investigation; Stella tells Ante that she's worried Emelie is selling sex to a cop.

Interrogations by Regional Police Chief Ludvig Larsson are ongoing; Peter's group realizes that Conny had many caches; the blackmail is wider than originally thought.

Peter and Ulla pressure Ante in the interrogations; Emelie flees from the police, who are executing a search warrant; just as Peter is about to explain to Stella why they arrested Ante, he accidentally discovers something.