Isabel and Enrique debate peace terms at Guisando. King Juan II of Aragon, seeking Castilian support against France, sends his emissary Peralta to negotiate the marriage of his heir Fernando - to Juan Pacheco's daughter.

Isabel debates her marriage options. Her supporters want her to marry Fernando, and Enrique, the King of France's brother. Pacheco and the King count as an advantage that the devout princess won't lie to them.

Fernando travels under disguise to meet Isabel in Valladolid, keeping an eye out for bandits and Pacheco's men. Isabel grows afraid as the time to sleep in the wedding bed comes near. Gonzalo can't hide his jealousy.

Hearing good news from Rome, Enrique makes his new move by blockading Valladolid. With no food for the winter, the people's support for Isabel and Fernando vanishes. Fernando also grows sick of Carrillo's meddling.

Isabel and Fernando find refuge in Medina de Rioseco but their situation is dire. Pacheco's army is on the move, ready to punish their supporters. Fernando suspects of Carrillo, while news of her husband's infidelity drive Isabel mad.

King Juan convinces the new Pope to sign the bull authorizing Isabel and Fernando's marriage. Rome's envoy, Cardinal Borgia, also must propose a new Castilian cardinal - a position that Carrillo and Pedro Mendoza strive for.

Cabrera convinces the King to receive Isabel and Fernando in Segovia. Away from the Court, Pacheco offers Queen Juana his support while he plots to kidnap Isabel and her daughter.

Isabel's decision to take the Crown while Fernando is in Aragon angers him, a division that Carrillo is eager to use. Meanwhile, Diego Pacheco seeks support from Portugal and the nobles to dethrone Isabel in favor of Juana.

Isabel debates showing mercy to the rebels when the new bread tax causes an uprising in Segovia. Chacón ponders retirement. Juana feels imprisoned during her husband's absence and seeks solace in her stepson, the Prince of Portugal.

Isabel visits Seville, Castile's richest city but also a place plagued by crime and corruption. Juan II accuses Fernando of caring more for his wife's kingdom than for his. A border incident sours relations between Castile and Granada.

The King's long absence throws Portugal in confusion, but Isabel and Fernando are no less divided over their next move. Rome pressures Castile to adopt the Inquisition. In Granada, the jealous Aixa plots against the Emir.