In medieval Tallinn, a famous knight who is freed from the pirates of the Baltic Sea is murdered. The hero's head is cut off and his mouth is stuffed with coins. The gold chain he bought the same day is missing. The bailiff orders Melchior, an apothecary, to investigate the crime. The clever young man discovers that the slain was looking for a mysterious "Tallinn prisoner" and the traces lead to the Dominican monastery. A fabulous sequence of bloodwork is unleashed - anyone who comes into contact with this secret is in danger of dying.
In a moment of cowardice, Detective Carl Mørck sends Rose, his junior colleague in Department Q, to the remote Danish island of Bornholm to answer his old colleague Christian Habersaat's repeated requests. But during his forced retirement ceremony Christian kills himself sending Rose into a journey deep into her own traumatic past. Later, Department Q are embroiled into an old cold case of a girl found dead hanging in a tree.
In the middle of the night, a drunk town guard happens to meet the daughter of a rich merchant… who drowned herself into a well 10 years ago. Soon after the town guard falls dead from the tower. This is followed by two other suspicious deaths. Doubting the existence of the ghost, Melchior has a hunch that these ‘accidents’ are part of a heinous crime. Tracking down the killer, his path will cross with heretics, old feuds and dark family secrets.
