The wedding of Isabel and Fernando has been a success: many nobles support them, the people acclaim them and see in them the birth of a new Castile, but there are still many pitfalls. And time is against them, because they do not have a bull and that will make them unpopular.

Start a married life not easy. The fight with Enrique continues while Aragón continues to ruin. Isabel and Fernando are left without money and without support, how are they going to get to sit on the throne?

And winter comes. And the forecasts of Pacheco are met one by one. Without money, almost without food, Isabel and her family live moments of tension. Fernando begins to have friction with Carrillo that Chacón tries to avoid with difficulty. Hunger takes its toll on the people who go from hailing Isabel to try to assault her residence in search of food. The fervor of when her wedding has disappeared.

July 26, 1471: Pope Paul II dies in Rome. A few days later, Pope Sixtus IV is elected. It is time to unblock the situation of the bull of Isabel and Fernando. John II of Aragon sends his faithful Pierres Peralta to speak with the new Pope.

The influence of Aragon in Italian territories is of prime interest to Sixtus. Also, the provision of funds and the idea of an anti-Turkish crusade. Peralta brings economic congratulations (barely removed from the depleted arcas Aragonese: it is a bet to all or nothing face the future) to Sixto and tells him that he will always have Aragon in everything ... in exchange for the papal bull of marriage of his son Fernando with Isabel.

Sixto accepts: it's time to change. For this, he asks for advice from a cardinal he knows well as being Valencian (and belonging to the Kingdom of Aragon). Rodrigo de Borja. And he sends it to Castilla y Aragón to know the problems firsthand.