In 1903, Lady Emily and her husband, Colin Hargreaves are drawn to Italy by a series of burglaries that might have international ramifications. When a stranger is thrown to his death from the roof, Colin's trusted fellow agent, Darius Benton-Smith, arrives to assist in a top secret investigation. Finding herself excluded, Emily secretly launches her own inquiry, aided by her friend, Cécile. The palazzo may contain a hidden treasure dating back to the days of the Medici, but in this 15th adventure (after In the Shadow of Vesuvius), as Emily and Cécile race to untangle the cryptic clues, an unimagined danger follows closely behind.