He's Sweden's most prolific serial killer. Jurek Walter is serving a life sentence. Kept in solitary confinement, he is still considered extremely dangerous by psychiatric staff. He'll lull you into a sense of calm. Mikael knows him as "the sandman". Seven years ago, he was taken from his bed along with his sister. They are both presumed dead. He has one target left. When Mikael is discovered on a railway line, close to death, the hunt begins for his sister. To get to the truth, Detective Inspector Joona Linna will need to get closer than ever to the man who stripped him of a family; the man who wants Linna dead.