Phantom (2013)

When Harry Hole moved to Hong Kong, he thought he was escaping the traumas of his life in Oslo and his career as a detective for good. But now, the unthinkable has happened - Oleg, the boy he helped raise, has been arrested for killing a man. Harry can’t believe that Oleg is a murderer, so he returns to hunt down the real killer. Although he’s off the police force, he still has a case to solve that will send him into the depths of the city’s drug culture, where a shockingly deadly new street drug is gaining popularity. This most personal of investigations will force Harry to confront his past and the wrenching truth about Oleg and himself.