When one of his wife Paola's students comes to visit him, with a strange and vague interest in investigating the possibility of a pardon for a crime committed by her grandfather many years ago, Commissario Brunetti thinks little of it, beyond being intrigued and attracted by the girl's intelligence and moral seriousness. But when she is found murdered, clearly stabbed to death, Claudia Leonardo is suddenly no longer simply Paola's student, but Brunetti's case ...