Istanbul, 1840: the new sultan, Abdülmecid, has heard a rumor that Bellini's vanished masterpiece, a portrait of Mehmet the Conqueror, may have resurfaced in Venice. Yashim, our eunuch detective, is promptly asked to investigate, but -- aware that the sultan's advisers are against any extravagant repurchase of the painting -- decides to deploy his disempowered Polish ambassador friend, Palewski, to visit Venice in his stead. Palewski arrives in disguise in down-and-out Venice, where a killer is at large as dealers, faded aristocrats, and other unknown factions seek to uncover the whereabouts of the missing Bellini.