Late one night, Brunetti is called away from dinner to investigate the death of a widow in her modest apartment. Though there are some signs of a struggle, the medical examiner rules that she died of a heart attack. It seems there is nothing for Brunetti to investigate. But he can't shake the feeling that something or someone may have triggered her heart attack, 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.