In the year 1500, Duke Cesare Borgia desires to marry his sister to the heir apparent of Ferrara, which hinders his conquest of central Italy. On this sensitive assignment, he sends his sister's lover, Andrea Orsini, who is nearly as ruthless as himself. Camilla Verano, wife of the count of Città del Monte, threatens to turn Orsini against his lethal master, whom no one betrays twice.