Eugenia de Montijo, an extraordinarily beautiful woman, educated and intelligent daughter of the Count of Montijo, decides to start a European tour when she discovers that the Duke of Alba, whom she believed her suitor, actually intends for her sister. In Paris she meets Napoleon III, the future...
During the third Carlist war on Basque soil, Zalacaín, no frowns that his great enemy of the people pretend to love his sister, but he lives the reverse situation, in love with his sister.