Though this is fifth Harry Hole novel in Norway, it's only the third one in the US. While things seemed to be going well for Harry at the end of Nemsis (he had solved a high profile case, and received permission to pursue investigating his partner Ellen's death), he appears to have hit bottom in this one. An alcoholic, Harry has mostly been avoiding alcohol in the last two novels. When The Devil's Star begins, Harry is coming off a four week long bender, and would probably have continued even longer if his boss hadn't call him in on a case. While his boss, Moller, has been trying to cover for him, and even put him down as on vacation, it is the holiday season, so he has no one else to call but Harry for a new murder case. Worse, he has to partner him with Tom Waaler, and Moller knows that Harry suspects Waaler of being behind Ellen's death and a gun smuggling ring. It was one of the last things Harry had him told before disappearing for four weeks, a binge prompted by his inability to find any usable evidence to support his theory and bring Ellen justice.
At the crime scene, Harry and Tom discover a young woman, shot in her bathroom, index finger cut off. An odd mark on her eye turns out to be a small, red diamond in the shape of a star or pentagram placed there by the killer. Harry soon gets drunk again, and Moller puts in the paperwork to get him suspended from the force. While waiting for the final decision, Harry uses a call by a distraught husband about a missing wife to get out of the office, and soon realizes that the police force actually has a serial killer on its hand, and that the wife is the second victim.
The rest of the novel follows the pursuit of the case, the implosion of Harry's personal and professional life (he and Rakel, his girlfriend, are separated as a result of Harry's self destructive behavior), and Harry's desire to prove what he knows about Tom to the rest of the force without knowing who to trust. While I quite enjoyed the investigative piece of it and the mystery part, some of the things involving Tom towards the end just kind of went a bit all over the place with chases and intrigue. Fortunately, it was really only the last fifty pages or so, and didn't take away from the rest of the novel, and I enjoyed the rest of the novel. What I've found interesting is that so many of the negative reviews on Goodreads and Amazon say "he's no Stieg Larsson" simply because they're both Scandinavian and write crime thrillers. I really don't think it's an apt comparison - the Harry Hole novels are series of detective or police crime novels, like so many other series in the US, that just happen to be by Norwegian author and take place in Norway. I would say they are primarily mysteries, like any other series. Larsson on the other hand has a trilogy that tells one woman's story - yes, there is a mystery at the center, but it still seems like it's more about what happens to Lisbeth. The Hole series is a very well done myster/thriller series, though, and while there might be bits and pieces I could do without in the novels, overall they are very entertaining and engaging. Actually, a certain plot point reminded me of a case involving a classic mystery character. I'm curious to see where the series goes from here since Harry lays at least one demon to rest by the end.