Invited by Commissario Guido Brunetti to dine at his in-laws’ palazzo, opera star Flavia Petrelli confesses her alarm at the excessive displays of adoration from an anonymous fan. When a talented young Venetian singer who has caught Flavia’s attention is savagely attacked, Brunetti begins to think that Flavia’s fears are justified in ways neither of them imagined. He must enter into the psyche of an obsessive fan before Flavia, or anyone else, comes to harm.