In the opening of Episode 4 of Jo Nesbø's Detective Hole, the story unfolds in Prague, where a woman confronts her partner about infidelity. She doesn't deny it, and as he leaves, she touches her necklace, a pendant with a star-shaped diamond that echoes the one found under Camilla's eyelid.
Agnes meets Eddie, the Chairman of the Justice Committee, to discuss the issue of cops carrying service weapons while off duty. During their meeting, Møller calls Agnes to inform her about the finger delivered to the station. He suggests bringing Harry back, citing his experience and tenacity for this case.
At the bar, Harry confesses to Vibeke that he misses Rakel. Vibeke wishes she could love her husband, Anders, the same way. When a group of men harass Vibeke, Harry gets angry but she stops him and shifts the conversation to Camilla's case. Harry asks Vibeke about Lisbeth, but she denies knowing her. After Vibeke leaves, Harry beats up the men who were harassing her. He is later arrested for the bar fight, where Tom visits him.
At the station, Tom tells Harry about Lisbeth's finger and repeats his offer to work together. Harry asks if he killed Ellen, but Tom denies it and claims that Sverre was responsible. He admits to killing Sverre after finding Ellen's body and staging the crime scene. Tom talks about his childhood and presents himself as someone who follows a strong moral code. He asks Harry to join him and promises financial reward in return for helping the community.
The next day, Tom briefs his team and informs them about Lisbeth's finger. He claims that the ring contains a star-shaped diamond similar to the one found in Camilla's case, linking the two victims. He also defends Harry when a younger officer disrespects him.
Later, Harry meets Willy at a theatre where he is directing Lisbeth's twin sister, Toya. Willy is devastated when Harry suggests that Lisbeth may have been murdered and that the finger could belong to her. Meanwhile, Maya calls Harry and tries to get information, but he refuses to meet her. As he walks past the bar he frequents, he is surprised to see Oleg waiting inside.
Oleg implores Harry to reunite with Rakel, but she refuses due to his self-destructive ways. A devastated Harry accompanies him to watch him dive. Meanwhile, Barbara, a woman working at the ABC Debt Collection office, is brutally murdered by an unidentified assailant. The police are called to the scene of the crime, where Harry and Tom investigate Barbara's body. Tom's touch of the still-warm corpse unnerves Harry.
As Tom departs, Harry notices that Barbara is missing a finger and is wearing star-shaped diamond earrings, similar to those worn by Camilla and Lisbeth. Beate discovers that the diamonds are not locally sourced but imported from Eastern Europe. Harry contacts Møller and informs him that they are dealing with a serial killer and urges him to assign the entire police force to the case.
Outside, Maya approaches Harry, but he refuses to speak to her. He searches the area around the crime scene and enters a pawn shop, asking the shopkeeper about any suspicious visitors, but receives no useful information. Meanwhile, Sissel, a cop, informs Harry about a Dearpmis gang member who was admitted to the hospital after the recent gang war. Harry visits the man and pressures him into revealing how the gang obtained flamethrowers.
Elsewhere, Tom attends a committee meeting at a church, where the leader speaks about taking matters into their own hands to maintain order. The episode ends with Tom leaving the church and beating up a group of drug addicts who were robbing a man.
