The following version of the novel was used to create this study guide: Nesbo, Jo. Knife. Knopf, July 9, 2019.

In the novel Knife by Jo Nesbo, detective Harry Hole believes his life is over when his estranged wife, Rakel, is found murdered. He has no idea that things will get much worse.

Harry had sunk back into his old habit of drinking heavily after Rakel asked him to leave their house. One night, Harry’s friend, Bjørn Holmes, had to take Harry home because Harry was so drunk and had gotten into a fight with the owner of the bar. Harry later learned it was that night that his wife was murdered.

After Harry visited the murder scene and learned that the wildlife camera he had put outside the house and told no one else about had been destroyed and the memory card taken, Harry began having strange memories that he could not put together. He saw Rakel’s dead face in his mind even though he had intentionally not looked at her face at the murder scene. He had memories of lying on the floor where Rakel was killed, looking up at the chandelier, and realizing that it made the shape of an “s”.

Because Harry was not allowed to investigate Rakel’s death, Harry started his own investigation. He believed at first that Svein Finne, a serial rapist whom Harry had put in jail for 20 years, was responsible for Rakel’s murder. Harry’s suspicion was strengthened when Harry realized that he had killed Finne’s son, Valentin Gjertsen, a serial murderer, in the line of duty. Finne was freed from police custody, however, when it was determined that he had an alibi for the time that Rakel was killed.

Next, Harry set his sights on Rakel’s boss (Roar Bohr) after Harry determined that a boot print outside Rakel’s home matched a pair of unique Soviet military boots that Bohr wore. Harry ruled Bohr out when he learned that Bohr’s sister had been raped. She had later killed herself. Bohr had never forgiven himself and made it his life’s work to avenge her rape and try to keep other women from being attacked. Rakel was one of the women on whom he kept an eye.

Peter Ringdal, with whom Rakel had once worked at the Jealousy Bar, was Harry’s next suspect. Harry found Ringdal’s fingerprints on a glass in Rakel’s house. He broke into Ringdal’s house and discovered a photo of a dead girl posted above Ringdal’s desk in a locked office in the basement. Harry interrogated Ringdal and discovered that Ringdal had hit the girl with his car during a snowstorm when he was young and drunk. He had manipulated the situation so that he was not convicted of killing her. However, he continued feeling guilty for her death. He dedicated his life to creating a system of centrally controlled carriages to replace human-driven cars as a way to pay for what he had done and, perhaps, save the lives of others.

Having exhausted his list of suspects, Harry had his friend Ståle Aune, who was also a psychiatrist, hypnotize him. While Harry was under hypnosis, he remembered waking up next to Rakel’s dead body and then driving his car away from the scene. Harry believes that he blocked out the memory of murdering Rakel because he did not want Oleg, Rakel’s biological child and Harry’s step-son, to have to lose both his parents. With Oleg still in mind, Harry decided to kill himself. He would make the suicide look like an accident.

Harry intended to drive into the path of a big truck. The trunk sounded its horn when Harry swerved into its lane. Harry turned on the radio to drown out the sound of the horn. Instead of the hard rock music he always listened to, the radio was tuned to a country station. Harry attempted to save himself at the last moment. Though he did not hit the trunk, he lost control of his car. The car flipped into a river and went over a waterfall.

Officers at the scene of Harry’s crash were stunned that he survived. Remarkably, Harry did survive the crash and intended to confront the man who had killed Rakel. Harry called Alexandra Sturdza at the forensics lab and had her test his blood on the pants he wore the night Rakel was murdered for Rohypnol, a powerful tranquilizer. He had her send the results to Bjørn and then called Bjørn to ask for a ride. Bjørn was surprised to learn that Harry was alive and even more surprised when he learned that Harry knew he had killed Rakel.

Harry told Bjørn that one of the factors that had led him to determine that Bjørn had killed Rakel was the country music on the radio. Harry knew that Bjørn could not drive without listening to country music so he reasoned that Bjørn had driven Harry in Harry’s car to Rakel’s house the night she was murdered with the intent of making Harry believe he had killed his wife. Harry had also learned that Gert, the boy born to Katrine while she was married to Bjørn, was Harry’s biological son. Gert was the result of one night an intoxicated Harry had spent with Katrine while Rakel was in the hospital.

The story ends with Bjørn killing himself and Harry learning from Johan Krohn (Finne’s lawyer) that Finne admitted to raping Bohr’s sister. Harry and Krohn set Finne up to believe that he would be meeting a girl he wanted to rape. In reality, Bohr was waiting with his sniper rifle for Finne to appear. Bohr killed Finne, who was later accused of having killed Rakel when new information showed that Harry had been drugged, and that Rakel might have been killed earlier in the day than first suspected.