Fernando sends his son, Sancho, with a small army to Zaragoza to confront his brother, Ramiro, the King of Aragon. Before leaving with Sancho, Ruy reveals to the King that Flaín tried to kill him. Fernando starts to investigate who betrayed him. Meanwhile, Ruy leaves León ignorant to the fact Flaín sent a hitman within the troop to kill him.

The Castile tropos with Sancho and Ruy fight an outnumbered battle against the Aragonese. When all seems lost, the outcome seems totally unexpected. In León, Fernando discovered who was conspiring against him.

After Fernando’s subsequent illness, Sancho and his troops return to León. Ruy tells his grandfather that Flaín sent someone to kill him. Rodrigo knows his grandson’s life is in danger. Flaín, on the other hand, doesn’t give up on his mission to conspire against the dying King and decides to attempt seizing power before his death. He is unaware that Urraca still has a card to play.

After the assassination of Flaín, the Count of Leon, many point at Ruy as the culprit. Meanwhile, the one from Vivar is forced to go back to Zaragoza, where he was sentenced to death for having lain with Amina, the Emir’s daughter. In Leon, Urraca finds out that Jimena and Ruy are in love, and schemes a plan to gain benefit from this information.

Alfonso, following Urraca’s advice, has one last tempting card up his sleeve to get Ruy to stay in Leon by his side: breaking off Jimena’s betrothal to Orduño and blessing her marriage to Ruy. Ruy will get everything he wants, but in exchange he will have to betray Sancho. Meanwhile, the Arabs, who are looking to destabilize the Christian kingdoms, tell Sancha that the King was poisoned.

After Sancha’s death, the war between the three brothers is imminent. Sancho sets out to attack Galicia, but in order to do that he must pass through Leon. Alfonso can’t decide whether to leverage that moment and attack him or to let him through. Meanwhile, Ruy struggles with the passion between him and Amina, and the pain that Jimena’s betrothal to Orduño is causing him.