The imaginary city of Vetusta, a symbol of anachronistic and oppressive traditions, is the realm of hypocrisy and intolerance that makes Ana Ozores's life unbearable and inevitably tragic.

Adapted from the novel of the same name by Clarín, which narrates the difficulties of Ana Ozores to adapt to the sordidness of life in Vetusta, a provincial city of northern Spain inspired in Oviedo. The young Ana, married to a retired regent, lives oppressed by the provincial hypocrisy and the mystical fears of an absorbing religion. Sexually dissatisfied, beset by constant erotic dreams, she reveals in her confessional her intimate torments, and her confessor begins to feel a morbid passion for her. At the same time, Álvaro Mesía, a Don Juan, intends to seduce Ana.