The Santa Cruz dry-goods store, founded in the eighteenth century and located in Madrid, is the source of income for Juanito Santa Cruz. Though he graduates from the university at twenty-four, he is not yet inclined to join the family business, preferring instead to indulge in the pleasures of life. His mother, Barbara Santa Cruz, dotes on him, guided by her advisor, a former clerk named Placido Estupiñá, who also engages in smuggling on the side.

An Unconventional Affair

Juanito meets the captivating Fortunata at a fellow student's home, and she soon becomes his mistress. Their affair is soon discovered by Estupiñá, prompting Juanito's mother to arrange a marriage for him with his beautiful yet passive cousin, Jacinta. They wed in May 1871, and upon returning from their honeymoon, Fortunata departs from Madrid.

Infertility and Intrigue

In the years that follow, Jacinta learns she cannot have children. Upon discovering details of Juanito's past affair, including Fortunata bearing him a son, Petusin, she contemplates the possibility of adopting the child. Meanwhile, Juanito learns Fortunata has returned to Madrid, but before he can find her, he falls seriously ill with a lung infection.

Admiration and Marriage

Among Fortunata's admirers is the unattractive and troubled Maximiliano Rubín, an orphan raised by his Aunt Lupe, who indulged his imagination despite his frequent headaches. While studying pharmacy, he meets Fortunata, whose impoverished state allows her to overlook his physical shortcomings. She eventually confesses her past to him, and in a bid to redeem her, he proposes marriage.

Fortunata's Redemption

Aunt Lupe, upon learning of Maximiliano's intentions, sends his brother, a priest, to counsel Fortunata. She admits that Maximiliano is the only lover she ever cared for, except for one who is now married. The priest suggests she spend time in a home for troubled girls before consenting to the marriage. After a period in this institution, Fortunata weds Maximiliano, who is plagued by severe headaches.

Reuniting with a Former Lover

Anticipating the marriage, Juanito rents a room at the boardinghouse where Fortunata and her husband are to reside. Initially, he only wishes to see Fortunata again, but when Maximiliano is incapacitated by illness on their wedding night, Juanito and Fortunata rekindle their old relationship. The affair leads to a confrontation between Maximiliano and Juanito, ending with the pharmacist hospitalized and Fortunata leaving her husband.

Public Exposure and Consequences

Maximiliano's brother, Juan Pablo, spends his days in cafés with companions like the elderly Colonel Evaristo Feijóo. During a parade marking the monarchy's restoration in 1874, Juanito and Fortunata are spotted together, sparking a scandal. Jacinta discovers the infidelity and confronts Juanito, who wins her sympathy for Fortunata's mistreatment by her husband. Although he promises to end the affair, Fortunata is enraged by his farewell letter and monetary gift, leading her to confront Jacinta.

A New Alliance

Fortunata's anger fades upon seeing Jacinta's gentle beauty, and Colonel Feijóo advises her on her limited options: return to her husband, become a mistress to wealthy men, or choose him as her protector. She opts for Feijóo, hoping to secure her future and regain the favor of the Rubín family. An encounter with Jacinta leaves Fortunata torn between admiration and resentment, leading her to reveal her identity.

Confrontation and Reflection

Guillermina Pacheco intervenes and invites Fortunata for a discussion, which Jacinta overhears. The revelation that Fortunata bore Juanito a son deeply wounds Jacinta. Despite Fortunata's anger, she remains a woman shaped by her lower-class roots.

Descent and Tragedy

After a tumultuous confrontation with a deteriorating Maximiliano, Fortunata returns to Juanito. Maximiliano, unable to keep a stable job due to his...