Commissario Brunetti does not have much to do when his boss is on a holiday, and Venice is just waking up from its winter sleep. But then the machinations of the church begin to cast their shadow over his professional and private life. Suor Immacolata, the beautiful, self-sacrificing Sicilian nun who looked after his mother has left her religious order with a terrible suspicion after the unexpected deaths of five patients. Brunetti makes enquries in the churches and hospitals, looks for the dead people's heirs, and soon finds himself in a labyrinth of religous faith and hypocrisy. He encounters a colourful motley of people, but he cannot find a convincing suspect. Fortunately, Brunetti's network of informers and his wealth of ideas are almost as effective as the influence of the church...