"An emergency call comes in the middle of the night. There is an ongoing burglary at a closed campsite in Bredäng, outside Stockholm. When the police respond to the call, there is a light on in one of the farthest caravans in the otherwise dark area, where the officers are greeted by a horrific sight. The floors, walls, and furniture are completely covered in blood. A person has been killed with an axe and brutally dismembered. In one of the rooms, a young man is sleeping on the floor with a severed arm as his pillow. He is arrested and taken into custody at Kronobergshäktet. There, he is identified as seventeen-year-old Hugo Sand, the son of a famous author. It turns out that Hugo is suffering from a rare kind of somnambulism, which is triggered by nightmares. He is either the perpetrator or a witness but claims that he remembers nothing from that night. When Joona Linna is asked to take on the case, he contacts his old friend Erik Marie Bark to use hypnosis in the quest to find out what happened inside the caravan. This is the start of a complicated hunt for a terrifying killer who has just entered an extremely active phase."-- Provided by publisher.