Lucrezia is poised to marry the Duke of Ferrara, meeting with his representatives who seek to adjust the terms with the pope to their advantage. As meetings proceed, Cesare captures the man who writes calumnies of all the members of the Borgia family, torturing him to reveal his paymasters. The pope insists the cardinal accompanying Ferrara's men do the negotiation and intimidates him into favorable terms. Reluctantly, Lucrezia is required to leave her sons in Rome when she weds. Cesare returns to his plans to conquer the rebellious states: Florence, Naples, et al, with the help of machines designed by Leonardo da Vinci. During the summer retreat of the pope, Cesare has a political prisoner garroted. Niccolo Machiavelli observes him and later uses Cesare's exploits to illustrate what a Renaissance statesman should do, in his classic book, The Prince. Lucrezia is pregnant for the third time, and Jofre's wife Sancia is sent to the Castel Sant'Angelo after accusing the pope as a murderer.