It is, together with Leopoldo Alas y Ureña's La Regenta (The Judge's Wife), one of the most popular and representative novels of Spanish literary realism.

Born in Las Palmas de Gran Canaria, Canary Islands, the author went to Madrid, the capital, to study law at age 18.

While criticized by political and religious leaders, it was praised by peers of Galdós for its realistic depiction of life amongst all classes in 19th century Madrid.

The story revolves around Fortunata and Jacinta, two women of different classes who claim Juanito Santa Cruz as their husband.

Worried about Juanito's lifestyle, his mother decides to marry him to his cousin Jacinta and arranges a series of meetings between them that end in marriage.

Ido del Sagrario is a poor man whom Juanito invites to the house with the intention of humiliating him for his own amusement.

After consulting with Guillermina Pacheco (a saintly neighbour), the two women go to one of Madrid's poor neighbourhoods to see the boy, "Pitusín".

Jacinta rallies and tries to raise Pitusín, but her despair from the deception and the wild manners of the boy are too much for her and she ends up sending him to an orphanage.

Soon the young man proposes to maintain her, and Fortunata, seeing this as an opportunity to escape her situation, accepts his offer.

Everyone agrees that Fortunata should spend some time at Las Micaelas, a convent that houses and tries to reform "fallen" women.

However, a trap awaits Fortunata in her new home: Juanito Santa Cruz has bought the apartment next door, and he bribes the newlyweds' servant to sow discord between the couple.

Maxi gradually loses his mind and develops a fatalistic desire to kill himself and Fortunata, as well as other members of the family, to "free" them from what he sees as the "beast", i.e. life and its associated suffering.

Rather than explain to Doña Lupe what has happened, Fortunata simply gets out of the house and returns to her Aunt Segunda, at the place she was raised.

Jacinta receives the child gladly and also learns the true reason of Fortunata's death and of her husband's many betrayals.