For Sierva María de Todos los Ángeles, existence is precarious from the very beginning. The only child of the funereal second Marquis de Casalduero, Don Ygnacio de Alfaro y Dueñas, and his drug-dependent wife, Bernarda Cabrera, Sierva María is so puny at her premature birth that the African slave to whom she is later entrusted promises the Virgin Mary that if God permits her to live, the girl’s hair will not be cut until she marries. Abandoned thereafter to a half-savage upbringing while the listless marquis withdraws further from society, and his commoner wife finds solace in her fermented honey, cacao, and many lovers, Sierva María grows up a phantasmal and enigmatic creature, illiterate and prone to lying. On the fateful eve of her twelfth birthday, she is one of four people bitten by a dog later discovered to be rabid.
As terrible suffering and two deaths ensue among the other victims and news of his daughter’s possible infection reaches his ears, Don Ygnacio undergoes a change of heart, regretting his inexcusable neglect of Sierva María. He retrieves her to live in their decayed ancestral mansion and sets out to investigate optimal treatments for her. Returning horrified from the Amor de Dios Hospital, where a sufferer of the dog bite lies half-paralyzed and dying, Don Ygnacio encounters the blasphemous licentiate Abrenuncio de Sa Pereira Cao, a doctor infamous for his unconventional ideas and remedies, whom he convinces to examine Sierva María. Abrenuncio’s prognosis is far from alarming: The girl is unlikely to contract rabies and should be made as happy as possible in her new home.
For a while, all goes well as father and daughter gradually forge a relationship and discover a shared interest in music. Eventually, however, Sierva María comes down with a strange fever and is subjected to the torturous medical remedies of her day. Abrenuncio counsels the marquis on the uncertainties inherent in science as well as faith, and the situation appears resolved until the bishop of the diocese, Don Toribio de Cáceres y Virtudes, troubled by reports of the girl’s odd behavior, summons Don Ygnacio to his palace for a religious consultation.
Sierva María may be possessed by demons, the bishop affirms, and in spite of her father’s doubts ought to be transferred to the Convent of Santa Clara for immediate spiritual attention. At the convent, the silent, long-haired girl is at first ignored or treated as an oddity by the nuns and novices under the direction of the embittered Abbess Josefa Miranda, whose long-standing grudge against the Holy Office predisposes her to dislike to Sierva María. The girl’s virtual imprisonment coincides with more violent, inexplicable behavior, and when rumors of peculiar occurrences at the convent reach the bishop, he appoints Father Cayetano Delaura to exorcise Sierva María of demonic possession. Delaura, an aspirant to the post of Vatican librarian, declares his reluctance to undertake a task for which he considers himself unqualified. The bishop, however, insists on his participation and dispatches him to the convent.
An avid reader of books both ecclesiastical and forbidden, Delaura is skeptical about the Holy Office’s conclusions concerning demonic possession. In treating the captivating Sierva María, he relies principally on smuggled pastries, consoling blandishments, and quotations from the Spanish Renaissance sonnet writer Garcilaso de la Vega. The young priest is moved to see her strapped down inhumanly in her own filth; with the help of Martina Laborde, her cellblock companion, he slowly manages to win her confidence. The arrival of a new viceroy, Don Rodrigo de Buen Lozano, who declares an era of renovation, prompts a more gentle handling of the supposedly possessed girl, whose beauty affects him as much as it has Delaura.
When the bishop finally orders Delaura to carry out the exorcism, the wavering priest, fighting his own demons, pays a surreptitious visit to the apostate Abrenuncio to confer on his crisis of conscience. Later in her cell, Delaura informs Sierva María that her father wishes to see her; she reacts frantically, spitting repeatedly in his face. This so excites Delaura sexually that the bishop discovers his acolyte flagellating himself to be rid of his own “possession.”
Despite being condemned to serving at the Amor de Dios Hospital for lepers as penance for his temptations, Delaura secretly visits Sierva María nightly in her convent cell, sneaking through a hidden sewer entrance left from the days of the convent’s battle with the Holy Office. Martina Laborde’s untimely escape, however, leads to the discovery and closing of this breach and thus to the cessation of the marriage-minded couple’s nocturnal encounters of poetry and cakes. The bishop’s hastened attempt at exorcism ends inconclusively in a sudden asthma attack; a second attempt by the priest of the town’s slave neighborhood, Father Tomás de Aquino de Narváez, ends equally suspiciously in his unexplained drowning. Finally, emaciated and weakened after five sessions with the bishop and shorn of the flowing hair that...