At the conclusion of the last book in this series, The Leopard, Harry Hole, no longer on the Oslo police force, retreated to Hong Kong where he built a new life. But three years later, his past calls him home. Oleg, the son of his former lover, Rakel, has been arrested for allegedly killing a drug dealer who was also his friend and the foster brother of the young woman that Oleg loved. The evidence seems incontrovertible, but Harry comes back to Norway in an effort to prove that Oleg is not guilty and to find the real killer.
In his absence, the boy who once called Harry "Dad," has fallen into a life of addiction and crime as a powerful new drug called Violin has swept through the city. Harry is someone who understands the power of addiction and, now clean and sober, he sets himself to the task of saving this boy that he loves.
Without the power of the police force behind him, Harry faces a seriously uphill struggle and the effort takes him deep into the shadowy world of drugs, criminal gangs and the police and politicians who either attempt to resolve the problem or to capitalize upon it. It's a gripping story that leads to a shattering climax, and Nesbo teases out the story in a way that's almost as addictive as the drug at the center of it.
It's a powerful novel and a great read but one cannot emphasize enough the importance of reading this series in order. The reader new to the series certainly does not want to start here. Admittedly, the first two books in the series,The Bat and Cockroaches are a bit weaker than the ones that follow, but at a minimum, one should start with the third book, The Redbreast before moving on. The principal attraction of these books is the character of Harry Hole and the world that surrounds him and no reader would want to deprive him or herself of the pleasure of watching these relationships unfold in order.