Late one night, Commissario Guido Brunetti's telefonino rings. A woman's body has been found in a Spartan apartment on Campo San Giacomo dell'Orio. Brunetti sees some signs of force on the old woman, but they could just as easily have been from the radiator near where she fell. When the medical examiner rules that the woman died of a heart attack, it seems there is nothing to investigate. But he can't shake the feeling that perhaps the woman was threatened.

Conversations with the woman’s son, her upstairs neighbor, and the nun in charge of the old-age home where she volunteered do little to satisfy Brunetti’s nagging curiosity. With the help of Inspector Vianello and the ever-resourceful Signorina Elettra, perhaps Brunetti can get to the truth and find some measure of justice.