General Taddeo Bottando of Rome's Art Theft Squad is in trouble: his theory that a single master criminal, dubbed "Giotto" - for the fourteenth-century Florentine painter about whom little is known - is behind a string of major thefts has aroused the scorn of his archenemy and rival, the bureaucrat Corrado Argan. Some clever thief has stolen more than two dozen paintings since 1963, always choosing unphotographed works that would be difficult to identify. Bottando thinks he sees a pattern, but a recent arrest means he may be wrong, and the hated Argan, who clearly wants Bottando's job, may be right again. Bottando is fortunate in his supporters, however - especially in Flavia di Stefano and her friend, English art dealer Jonathan Argyll. When a strange letter arrives on Bottando's desk, he hopes that the confession of a dying woman may provide just the clue he needs to find the mysterious Giotto. As Flavia hurries to Florence to interview the writer of the letter, the elderly Maria Fancelli, Jonathan sets off for England, where he will meet with Geoffrey Arnold Forster, a man who may hold many of the answers if only he will share them. But when Jonathan arrives in Norfolk, he discovers a body and a mystery that could lead to the greatest art find of his career.