Juan returns from Spain. Rodrigo is impressed by his son’s newfound confidence and orders him to lead the Papal armies to besiege Catherina Sforza’s castle.
Lucrezia meanwhile, stalls attempts to marry her off – her father favors rich Genovese merchant prince Calvino – but Lucrezia, obstinate and deliberately perverse, proceeds to flirt with his younger (and thus inappropriate) brother Raffaello.
In Florence, Cesare and Machiavelli witness Savonarola’s puritan zealots strengthen their grip on power, culminating in the fevered destruction of art works and luxuries in the “Bonfire of the Vanities.”
Meanwhile, Juan’s siege of Forli reaches a stalemate until he manages to kidnap Catherina’s son Benito, whom he tortures and threatens to kill in view of the castle walls. Hernando is disgusted by this ignoble behavior and Juan’s true cowardly nature is revealed when he flees in terror as the siege is broken by a surprise attack by Ludovico Sforza’s reinforcements.