When Pope Alexander dispatches a Vatican courtesan, Damiata, to the remote fortress city of Imola to learn the truth behind the murder of his most beloved illegitimate son, she cannot fail, for the scheming Borgia pope holds her own son hostage. When Damiata becomes a pawn in the political intrigues of the pope's surviving son, she enlists obscure Florentine diplomat Niccolò Machiavelli and eccentric military engineer Leonardo da Vinci to help decipher the clues. (Bestseller)