A young girl is found murdered in the isolation room of a center for troubled teenagers. Her skull is broken, and her hands are on her face as if she were playing hide and seek with the killer. In an auxiliary building, the night shift nurse is found dead. She has been murdered with a hammer.
Despite an internal investigation pending against him, Inspector Joona Linna is ordered to observe the investigations as a mere observer. He quickly discovers that one of the center's inmates, Vicky Bennett, has disappeared. In her room, he finds a bloody blanket and a hammer stained with blood.
Shortly thereafter, the theft of a car with a four-year-old boy inside becomes known. Everything points to Vicky being responsible for the abduction. Thus begins a race against time for Joona Linna. What is Vicky Bennett capable of? And who is this woman who insists on calling the police, claiming to be a medium and seeing the ghost of the dead girl?

After "The Hypnotist" and "The Paganini Contract," "The Fire Witness" also remained at the top of the bestseller list in Sweden for many months and is being translated into more than 30 languages. As the newspaper Dagens Nyheter wrote, "you start reading this thriller on the subway ride home, continue reading while eating your dinner, and don't stop until the early morning hours."