It is Christmas in the alpine town of Furth am See and a six-year-old girl is playing ludo with her grandfather. The doorbell rings, and the old man goes to answer. The next time the girl sees him, he is lying with his skull broken, his face a red pulp against the white snow. From that time on, she does not speak a single word.

Raffael Horn, the psychiatrist engaged to treat the silent child, reluctantly becomes involved in solving the murder along with Detective Superintendent Ludwig Kovacs. Their parallel researches sweep through the town: a young mother who believes her new-born child is the devil; a Benedictine monk who uses his iPod to drown the voices in his head; a high-spending teenager who tortures cats. The psychological profile of this claustrophobic, winter-held town is not reassuring - which, if any, of its inhabitants was the brutal night-time slayer of the suffering girl's grandfather?