A beautiful young woman, Michela Licalzi, was found murdered in her villa in Vigate. Moreover, she is discovered during unauthorized entry into the house by none other than Commissioner Montalbano. Suspicion falls on the mentally disabled Maurizio Di Blasi, hopelessly in love with Michela. Commissioner Montalbano does not believe Maurizio is guilty, but he is removed from the investigation. Maurizio soon dies from a police bullet while trying to arrest him. It would seem that the case can be closed, but the truth-loving commissioner continues to look for the real criminal.