In the opening of Episode 9 of Jo Nesbø's Detective Hole, Tom abruptly abducts Oleg from Rakel's house in the dead of night. Simultaneously, Harry ventures to Willy's apartment complex, attempting to sneak into his house via the roof.
The serial killer in question is revealed to be Willy, who Harry enters his apartment to arrest for the murders of Camilla, Lisbeth, Barbara, and Marius. Harry explains that forensic evidence shows Willy used Lisbeth's severed finger during post-coital sex before sending it to the police. Willy confesses to hiding the finger within his body to evade detection by police dogs.
Willy commits the murders because Lisbeth was involved with Martin during their honeymoon in Prague. He recalls how Lisbeth and Martin exchanged letters and developed a relationship. Willy stages the murders at five-day intervals to frame Martin.
Willy attempts to escape by threatening Harry with a gun, but Harry discovers Lisbeth's body within the waterbed and Toya's body tied up in the bathroom. When Harry goes after Willy, he learns that Willy has jumped off the balcony and died.
As for Oleg, Rakel reports him missing while Tom sends a photo of Oleg to Harry's burner phone. Harry tells Rakel to go home and promises to bring Oleg back safely. He calls Tom and asks him to come to the student dorm where he is hiding Martin.
Elsewhere, Harry reaches the dorm and hides Willy's gun inside the elevator. He goes to Martin's room and handcuffs himself to him, sitting in the hallway while Harry asks Otto to start recording through the CCTV cameras. Tom arrives with Oleg, and Harry accuses him of killing Ellen, saying he will expose him using the CCTV footage. Tom forces Harry, Martin, and Oleg into the elevator.
As Harry enters the elevator, he frantically searches for the gun, only to realize that Tom has cleverly removed it. With a sinister gleam in his eye, Harry掏出一把刀，stabs Tom viciously and drags himself, along with Martin and Oleg, into the elevator. Tom, in a desperate attempt to thwart their plans, smashes the glass on the elevator door and tries to shoot them. A brutal struggle ensues, with Harry holding onto Tom's arm as he commands Oleg to press the button. The elevator begins to move, and Tom's arm is gruesomely severed. Harry, now free from Martin's grip, orders him to take Oleg outside. Leaving Tom trapped within the building, Harry seals his fate, and Tom eventually succumbs to his injuries.
Harry brings Oleg home and attempts to distance himself from Rakel. However, Rakel, with unwavering determination, stops him and begs him to stay. The truth is revealed: Willy is identified as the serial killer, and Toya is recognized as one of his final victims. Martin is arrested for smuggling, Eikeland is released, and Tom is declared dead. Møller informs Harry that he will not be charged for Tom's demise as the police seek to avoid public scrutiny on the case. Harry shares an exclusive update with Maya but asks her not to publish it unless something happens to him or his family.
Agnes approaches Harry to discuss the investigation. During their conversation, Harry realizes that the bicycle killer case was too meticulously planned and likely staged. This revelation leads him to suspect that a bank robbery from five years ago was also a carefully orchestrated scheme. He informs Beate, and they promptly arrest the victim's husband for orchestrating the robbery to eliminate his wife.
Agnes implores Harry to continue working with the police to solve future cases. The episode concludes with a startling revelation: Agnes is revealed as the leader of the committee that Tom once served. She whispers to her team to remain before returning stronger.
