When the papal apartments are burgled in 1901, Sherlock Holmes is summoned to Rome by Pope Leo XII. After learning from the pontiff that several priceless cameos that could prove compromising to the church, and perhaps determine the future of the newly unified Italy, have been stolen, Holmes is asked to recover them. In a parallel story, Michelangelo, the toast of Rome in 1501 after the unveiling of his Pieta, is commissioned by Pope Alexander VI, the last of the Borgia pontiffs, with creating the cameos that will bedevil Holmes and the papacy four centuries later. For fans of Conan Doyle's immortal detective, the game is always afoot. However, the great detective has never encountered an adversary quite like the one with whom he crosses swords in "The Vatican Cameos.".