Alexander and Cesare have reconciled; the Borgias are ready to move against their enemies; Catherina is determined to resist a siege; Cesare learns that Alfonso has become aggressive.

Micheletto kills his lover and disappears; Cesare races to rescue Lucrezia; Alfonso begins to drink heavily; Alexander and Mattai scheme to corner the market in Italian sulphur.

Pilgrims travel to Rome for the Jubilee year celebrations; Catherina wants to hinder the festival; Mattai's contacts destroy a Turkish fleet; Lucrezia sees a change in Frederigo; Micheletto learns his lover is a spy.

Cesare burns Constanzo's palace to contain the plague; Lucrezia seeks a Neapolitan power base for herself; one of the candidates for Ferdinand's replacement is accused of trying to kill the other.

Cesare lands in northern Italy; Catherina sends a plague-infested cloth to Alexander; Alexander taxes a newly arrived Jewish communtiy; Mattai gains the Pope's respect.

Cesare's diplomatic mission is a success; Bianca takes her own life; Alexander and Sforza conspire to repay Gonzaga; Lucrezia travels to Naples; King Ferdinand continues the refusal of recognizing Giovanni.

Cardinal Farnese discovers Versucci's theft; Alexander calls for a Crusade; Giulia arranges an orgy for the new Cardinals; King Ferdinand learns that Lucrezia's marriage has not been consummated.

The purged Cardinals are stripped of their titles and wealth; King Ferdinand refuses to accept Giovanni; Cesare considers an alliance with the old enemy; Alexander sticks to his plan; Lucrezia is abandoned on her wedding night.

Pope Alexander seeks revenge against the cardinals; Rufio is ordered to rally support from the mercenary warlords; Lucrezia becomes annoyed with her future in-laws.

Pope Alexander fights for his life; the cardinals fight for control of the papacy; Cesare and Micheletto track the assassin; Della Rovere prepares to make his move.