Pacified Old Castile, the queen travels to convulsed Seville to impose order and justice.There he must face those responsible for the chaos in the city: the Duke of Medina-Sidonia and the Marquis of Cádiz.

In Seville, Isabel is aware of the problem posed by the false converts and, also there, the Jewish doctor Lorenzo Badoz diagnoses her gynecological malignancy and suggests a small intervention. Beatriz de Osorio, niece of Beatriz de Bobadilla, joins the Court. The young, sweet and kind, becomes Elizabeth's confidant but shows an unusual interest for the king.

Meanwhile, in the Nasrid kingdom of Granada, Emir Muley Hacén falls in love with Isabel de Solís, a Christian captive. For love challenges Castilla. The emir's attitude alarms the jealous Aixa, the wife and mother of the Boabdil heir.

Infanta Juan has been born. He is a healthy and awake baby. However, the queen's physicist fears the consequences of a new pregnancy and imposes a severe test on the kings. Fernando, for his part, wants to resume the adulterous relationship with Beatriz de Osorio, despite the apparent opposition to it.Later he will discover that Bobadilla's niece conceals dangerous intentions.

In Granada, Muley Hacén intends to turn Nasr, the son he has fathered with Isabel de Solís, into an heir. To do this, he calls the court to his brother, El Zagal, aware of the bitterness accumulated by Aixa and afraid of the reaction that his decision may cause.