In an attempt to kill Niccolo di Chimici, Camillo arranges for a cook in the di Chimici kitchens to place poisonous mushrooms in the Duke's meal when Niccolo is dining with his second son, Carlo. The plan appears to be a success, though the Duke is saved thanks to the knowlege and expertise of Brother Sulien, the pharmacist-friar at Saint-Mary-among-the-Vines. In retaliation, Carlo enlists the aid of the di Chimici's spymaster, Enrico Poggi, and stabs Camillo's youngest brother, Davide, when Camillo and his brothers are out on an evening stroll. Enraged by Davide's death, Camillo swears to exact vengeance upon the di Chimici, despite promising his mother that he will not pursue the vendetta.
As the di Chimici weddings approach, Matteo and his surviving sons begin stockpiling weapons to defend themselves against the di Chimici. Camillo observes that a young boy and his mongrel dog have been often lurking near the di Chimici palace and recognizes the dog as the one that Davide had stopped to pet on the night he was murdered. When the dog begins snarling at Carlo di Chimici, Camillo realizes that Carlo had been responsible for killing Davide. When Carlo and his new bride, Lucia, leave the Church of Annunciation after their wedding, Camillo is unable to control his rage any longer and stabs Carlo in the chest. In response, Lucia strikes Camillo in the head with a nearby candlestick and Camillo is slit in the throat by Fabrizio di Chimici.
After the floods that began after the massacre at the Church of Annunciation begin to subside, Matteo and Graziella Nucci beg for the bodies of their sons, Camillo and Filippo. Though Niccolo refuses them, he is forced to comply when his brother Pope Lenient VI insists that the Nucci be allowed to give their son a proper burial and for them to bring the grievously injured Filippo into their care. However, Niccolo insists that Camillo forever be recognized as a murderer in Giglia and exiles the remaining members of the Nucci family.