Up at the villa, a well-known writer lies dead without a mark of violence on her. Her husband snores drunkenly nearby. Down in the city of Florence, Marshal Guarnaccia of the carabinieri has a suspect, but no specialized skill and no evidence. However, help comes from a forty-year-old repressed memory of a ragged child kneeling on grains of rice in the corner of the classroom: Vittorio, the son of the village prosititute, whose long-ago sufferings would lead the marshal to the solution of the mystery.