When Louise Masterson, a member of the famous Titian Committee, is found stabbed to death in a Venetian public garden, General Bottando of Rome's Art Theft Squad sends Flavia di Stefano to Venice to assist the local carabinieri. But it seems they don't want her help or expertise, and are convinced a Sicilian mugger is responsible for the killing. Flavia has other ideas and calls upon the services of English art historian Jonathan Argyll, who is in Venice to buy a picture from the Marchesa di Mulino's collection. When another member of the committee is found dead and the Marchesa's collection is stolen, Flavia and Argyll follow a tortuous trail to unearth the truth behind both the killings and the theft. In the process, not only do they stumble across another murder, but come close to unravelling a mystery from Titian's own life.