Because of a debt, industrialist Augusto Medeiros is forced to marry his only daughter, the sweet Rosália, with the fearsome Francisco de Montserrat, an authoritarian banker. Augusto's decision upsets his marriage to Leonor, who does not agree with his husband. However, Rosália fell in love with Adriano, a newly trained doctor who had met at a mask dance at the 1901 Christmas Eve, without knowing that he was the son of Mr. de Montserrat. Meanwhile, Montserrat keeps in his care a woman, Joana, considered as crazy, trapped in a room of his mansion.