Jo Nesbø’s crime novel The Devil’s Star, first published in Norwegian as Marekors in 2003, is the fifth installment in the internationally bestselling Detective Harry Hole series. It was the first novel in the series to be translated into English. The novel finds Detective Harry Hole at his lowest point, battling alcoholism and facing dismissal from the Oslo police force. During an oppressive summer heatwave, Harry hunts a serial killer who leaves a signature five-pointed diamond at each crime scene. The investigation plunges Harry into a dangerous two-front war against both an enigmatic killer and the corruption within his own department.

The novel explores themes including The Corrupting Nature of Revenge, Jealousy and the Desire to Control Women, and The Facade of Normalcy and Hidden Depravity. Before becoming a full-time writer, Nesbø was a musician, songwriter, and economist. His work has received numerous accolades, including the prestigious Glass Key award for the best Nordic crime novel. The widespread success of the Harry Hole series, which has sold millions of copies worldwide, led to a 2017 film adaptation of a later book in the series, The Snowman. In 2026, Netflix released a television series based on the plot of The Devil’s Star.

This guide is based on the 2011 Harper paperback edition.

Content Warning: The source text and this guide contain depictions of graphic violence, substance use, addiction, sexual content, physical abuse, death by suicide, mental illness, cursing, and emotional abuse.

Plot Summary

The novel takes place in Oslo, Norway, during a sweltering summer. Camilla Loen, a graphic designer in her late twenties, is found murdered in her apartment. Her index finger has been severed, and a tiny red diamond cut in the shape of a five-pointed star has been placed under her eyelid.

Crime Squad Chief Inspector Bjarne Møller, short-staffed during the summer holidays, assigns the case to Inspector Tom Waaler and forensics specialist Beate Lønn, then reluctantly summons Detective Inspector Harry Hole. Møller informs Harry that he is going to be dismissed from the police force in a few weeks’ time but can continue to work until his dismissal is formally processed.

Harry has spent weeks struggling with alcohol addiction after the collapse of his investigation into the murder of his colleague and close friend, Ellen Gjelten. Harry is convinced that Waaler is corrupt and responsible for Ellen’s death. Harry spent months building a case that Waaler is the mysterious man known as “Prince,” (the ringleader of an arms-smuggling network) and that he ordered Ellen’s killing to protect his secret. However, no one believes Harry’s theory since Waaler is a respected member of the police force. Harry’s relationship with his girlfriend, Rakel, has recently ended due to conflict about his drinking and fixation with finding Ellen’s killer; Harry desperately misses Rakel and her young son, Oleg.

A second case soon emerges. Wilhelm Barli, a theatrical producer, reports that his wife, Lisbeth vanished after leaving their apartment for a quick errand. Days later, the police receive a severed middle finger (confirmed to belong to Lisbeth) wearing a ring set with a star-shaped diamond. The matching mutilation and diamond link the cases, and Møller persuades Harry to work alongside Waaler, as Harry is the department’s only detective with serial killer experience.

A third murder follows five days later. Barbara Svendsen, a receptionist at a law firm, is shot in the back of the head in the office lavatory. Her ring finger is severed, and a star-shaped diamond is placed in her ear. A witness describes a bike courier leaving the office shortly before the body was found and Harry theorizes the killer disguises himself as a courier. Meanwhile, Waaler (who knows Harry is about to be dismissed from the police force) offers him a position in his criminal network.

Eventually, Harry notices the repetition of the number five in many elements of the murders: five-pointed diamonds, five fingers, five days between murders, killings at approximately five o’clock. He plots the crime scene locations on an Oslo map and discovers they form three points of a pentagram. The remaining two points indicate the locations of the next crimes: a student residence and an old house named Villa Valle. The latter is occupied by an elderly woman named Olaug Sivertsen. The police warn Olaug that she may be in danger, and rig surveillance cameras throughout the student building, anticipating the killer’s next attack.

Waaler leads a stakeout at the student building, but the killer does not appear. Harry finds the body of a student named Marius Veland, who was murdered five days before Camilla, bringing the serial killer’s total number of victims to four. Meanwhile, Beate uncovers information about Olaug’s son, Sven Sivertsen (who currently lives in Prague). Sivertsen has previously been convicted for smuggling and has given his mother a red, star-shaped diamond. He has also visited Oslo on the date of every previous murder. Given this incriminating information, Waaler arrests Sivertsen for the “Courier Killer” murders.

The press celebrates the capture, and Waaler becomes a media hero. However, Harry suspects that Sivertsen is involved in Waaler’s smuggling activities. This suspicion is confirmed almost immediately after Sivertsen’s arrest: Waaler tells Harry that he wants Sivertsen dead (ostensibly because he does not think the justice system will effectively punish Sivertsen). He gives Harry instructions for how to sneak into the cell where Sivertsen is being held and poison him. If Harry carries out this act, he will be permitted to begin working for Waaler’s secret criminal organization.

Harry plays along and goes to Sivertsen’s cell, where the latter insists he had nothing to do with the murders. He explains that he was framed: an anonymous client hired him to deliver weapons and diamonds to Oslo at five o’clock on each murder date. The guns and diamonds from each drop were then used in the next crime, linking Sivertsen to the crimes and ensuring he had no alibi. He admits that he has met with Waaler in Prague and sold weapons to him. Harry takes Sivertsen out of the police building and conceals him in the student residence where the first murder took place. He wants Sivertsen to provide evidence against Waaler, but Sivertsen will only do so once Harry catches the true Courier Killer (he is afraid of being convicted for the murders unless it is confirmed that someone else committed them).

Waaler frantically tries to locate Harry and Sivertsen. While trying to construct a case against Waaler, Harry obtains a photograph from Sivertsen’s girlfriend. The photo, taken in Prague, shows Sivertsen meeting Waaler, but Harry recognizes the setting and it prompts him to finally understand the Courier Killer case. He questions Sivertsen, who admits that he met Lisbeth while she and Wilhelm were honeymooning in Prague and had an affair with her. Harry feels increasingly sure that Wilhelm is behind all the murders: He wanted to punish both Lisbeth and Sven Sivertsen, so he killed the former, killed other random victims to create the impression that a serial killer was active in Oslo, and then meticulously framed Sven for the crimes. To bolster his case, Harry requests secret forensic testing of the excrement found under the nail of Lisbeth’s severed finger (it is already confirmed that the excrement came from Wilhelm, who has claimed it got there during a sexual encounter a few hours before Lisbeth vanished).

Harry leaves Sivertsen concealed at the student residence and goes to Wilhelm’s apartment to confront him. Wilhelm readily confesses to everything, revealing that he killed Lisbeth just before he reported her missing. Her body has been concealed within their waterbed. Wilhelm uncovered Lisbeth’s affair after he found letters exchanged between her and Sven and he wanted revenge. Wilhelm is unconcerned with revealing this information to Harry because he does not think the latter has any actual evidence. Harry reveals that the forensic testing of the excrement showed the presence of specific seeds from a bread that Wilhelm likes to eat for breakfast. If the excrement got there before Lisbeth was killed, there would not have been time for him to have already digested and excreted the seeds. The finger must have been in Wilhelm’s rectum sometime after Lisbeth’s disappearance.

Wilhelm admits that he hid the severed finger in his rectum after killing his wife and identifies the location of her body. Wilhelm points a gun at Harry but then takes his own life. Harry finds the body of Lisbeth’s sister, Toya, in the flat (Wilhelm killed her just before Harry arrived). Still in shock after the confrontation with Wilhelm, Harry receives a voicemail from Waaler, informing him that Waaler has abducted Oleg (the young son of Harry’s ex-girlfriend). Waaler threatens the boy and Harry arranges to meet them back at the student residence.

At the student residence, Harry and Sivertsen face off with Waaler and Oleg. Harry outwits Waaler and traps him with his arm pinned inside a descending elevator. The force of the elevator tears off Waaler’s arm, and he bleeds to death while Harry, Sivertsen, and Oleg remain safe. Once he confirms that Waaler is dead, Harry summons police and the press; Sivertsen is returned to protective custody. Harry returns Oleg to Rakel, who expresses her willingness to get back together. Harry is congratulated by senior officials in the police force and offered the opportunity to return to his job. Harry states that he is unsure and the novel ends with him reflecting on his future.