Jo Nesbø’s The Devil’s Star is the fifth novel in the internationally bestselling Harry Hole series. The novel builds on important plot events that occurred in the third and fourth books in the series (The Redbreast and Nemesis, respectively). In The Redbreast, Harry Hole and his partner, Ellen Gjelten, learn of an arms dealer who goes by the code name “the Prince.” The Prince is implicated in providing weapons to Norwegian Neo-Nazis. After intercepting a phone call meant for Tom Waaler, a fellow police officer, Ellen realizes that Waaler is the Prince. To avoid detection, Waaler has a neo-Nazi criminal named Sverre Olsen kill Ellen; he then plants evidence to make it obvious that Olsen was the killer. While arresting Sverre Olsen for Ellen’s murder, Waaler kills Olsen, later claiming he did so in self-defense.

While everyone else considers Ellen’s death to be resolved, Harry suspects that Waaler arranged the crime and then killed Olsen to conceal his role. In Nemesis, Hole further investigates Waaler and becomes convinced that Waaler is a corrupt arms dealer who is responsible for Ellen’s death. Waaler displays his willingness to conceal his secret identity when he kills Alf Gunnerud, passing this death off as a second instance of killing a suspect in self-defense during a violent arrest. Harry is eventually able to identify Roy Kvinsvik as someone who saw Sverre Olsen and Waaler together on the night of Ellen’s death. Nemesis ends with Harry showing Roy Kvinsvik a photo of Waaler, asking if he recognizes the man. The Devil’s Star features Harry’s ongoing attempts to persuade Kvinsvik to reveal what he knows, so that Waaler can be brought to justice for his role in Ellen’s death. 

The Redbreast and Nemesis also establish the romantic relationship between Rakel and Harry. The couple meet in The Redbreast and are immediately attracted to one another, although Rakel is initially hesitant to pursue the relationship because of a complex custody case involving her son and her former partner. This case is resolved in Nemesis, paving the way for a deeper relationship and the formation of a family unit. However, by the time the plot of The Devil’s Star begins (about six months after the end of Nemesis), Rakel and Harry’s relationship has collapsed.