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.

After Ruy’s decisive intervention in the battle, Sancho of Castile takes Galicia from his brother García. But this does not bring peace to the Iberian Peninsula. On the contrary: the final battle between Leon and Castile is approaching. Meanwhile, Ruy is forced to betray Amina.