At the start of the Sunday service, a massive crowd surrounds the Church of the Capuchins, a house of worship located in Madrid, Spain. A few are assembled out of piety or a wish to hear the sermon (some wish to listen to it for enjoyment, others for the sake of critiquing it). Most, however, are here to show off - the men are here to look at the women, and the women are here to show themselves.
Despite this lack of genuine devotion, the church is packed. An old woman moves among the crowd, unsuccessfully trying to find a seat and complaining loudly. However, when her younger companion speaks, two soldiers perched nearby are startled from their conversation. The young woman is remarkably beautiful, with fair hair and pale skin. She is dressed beautifully but modestly, and does not remove her veil. The two soldiers give up their seats so that the two women can sit.
One of the soldiers, named Don Lorenzo (also known as Lorenzo de Medina), strikes up a conversation with the young women; meanwhile, his friend Don Christoval (also known as he Condé d'Ossorio) distracts her chaperone. He discovers that is young woman is quite new to Madrid, though she answers him in monosyllables. He attempts to remove her veil, explaining that this is not the custom here, but the young woman rebukes him. However, the older woman (who is her aunt, named Leonella) teases the girl, Antonia, for her excessive modesty. Lorenzo removes Antonia's veil, and marvels at her stunning beauty.
The girl's aunt explains her complicated family background. Antonia's mother Elvira married a noble without the consent of his father, and lived with him for three years. However, the nobleman's father eventually found out, and Elvira and her husband fled to the West Indies. Elvira's family was not so lucky. The nobleman's father threw Elvira's father into prison, and kidnapped Elvira's little son; the family later heard news of his death.
For thirteen years. Elvira lived with her husband in the Indies, only returning to Spain when he died. Her father-in-law reluctantly offered her his son's castle in Murcia, and it is there that she lives with her daughter Antonia. However, the women have now come to Madrid to renew their stay in the castle: Elvira's father-in-law has died, and she must petition his younger son to allow them to stay in the castle. Lorenzo asks the name of the young Marquis whom they are petitioning, and Leonella replies that it is the Marquis de las Cisternas. Lorenzo exclaims that he knows him quite well, and will intercede on behalf of the ladies, who exclaim their gratitude.
Leonella asks why there is such a crowd in the church, and the men explain that they have all come to hear the sermon of Ambrosio, abbot of this monastery. Though he has preached only three times before, his fame has spread throughout the city, and he is the most popular confessor in the area. His origin is somewhat mysterious: he was abandoned as an infant on the steps of the cathedral. He took his vows as soon as he was able, and soon became renowned for his great asceticism and his inspiring religiosity. Ambrosio appears before the crowded church. He has a commanding appearance and austere presence, and young Antonia feels an unfamiliar fluttering in her stomach when she lays eyes on him. He holds forth on the merits of religion, extorting his flock to abandon their sins and move towards righteousness. The crowd is transfixed, and many of them kiss his garments. Antonia sheds a tear when he leaves, and confesses her great admiration for the monk to Lorenzo. Leonella is more skeptical - she thinks he is too severe. The group prepares to leave, and Leonella flirts shamelessly with Christoval, certain that he is in love with her and suggesting that he propose marriage to her.
After the women depart, Christoval expresses his dismay at the old woman's attentions, and Lorenzo confesses his deep attraction towards Antonia. He wants to marry her, which shocks Christoval. Lorenzo explains that Raymond de las Cisternas (the current Marquis de las Cisternas, and Antonia's uncle) will likely agree to the match. Next, the two men continue on the mission that brought them to this area of the city - visiting Lorenzo's sister Agnes, who recently took vows and became a nun. Christoval teases him, saying that it's a waste that such a beautiful (and wealthy) girl took vows, but Lorenzo snaps at him so harshly that Christoval leaves the church. Plunged into melancholy by the argument with his friend and the departure of Antonia, Lorenzo reclines on a pew in the church and falls asleep just as dusk arrives. He has a terrible dream in which Antonia, clad in bridal white, is seized by a monster right before she marries Lorenzo. However, Antonia frees herself from the monster, sprouting angel's wings and ascending to heaven. Lorenzo wakes with a start.
As he is about to get up and leave the church, Lorenzo notices a cloaked figure sneak in and slip a letter under the statue of Saint Francis before hiding behind a pillar. Lorenzo suspects a love affair, but he does not want to intrude upon the stranger's privacy.
Outside, his friend Christoval accosts him, excitedly proclaiming that a train of nuns is on their way; their Prioress is leading them to confession with Ambrosio. Christoval is delighted at the chance to see these beautiful women unveiled, and he drags Lorenzo back inside the church. The two men watch the procession. One of the nuns drops her rosary just as she is passing the statue of Saint Francis, and as she bends down to pick it up she snatches the letter as well. A flash of light illuminates her face, and Lorenzo is horrified to see that it is his sister Agnes.
Recalling where the cloaked stranger hid, Lorenzo rushes at him in a fury, quick to defend his sister's honor. He exchanges several sword blows with the stranger before Christoval halts the violence; Lorenzo recognizes the stranger as Raymond de las Cisternas. Raymond proclaims that he loves Agnes and Agnes loves him, and the three men retire to the Hotel de las Cisternas to discuss the situation further.
The narrative moves back in time to when Antonia and Leonella leave the church. Leonella chats happily about the two young gallants; she is certain that Christoval is in love with her. When the women arrive at their apartment, they discover a shocking surprise: a gypsy woman is performing an elaborate dance in the street, surrounded by a great crowd. In verse, the gypsy woman proclaims her ability to read the future, and even to perform magic.
Leonella is dismissive of the gypsy woman (even making comments about how all gypsies should be burned to death), but Antonia begs her to pay the woman to read their fortunes. The gypsy women reads Leonella's hand, offering her a cruel fortune - the old woman isn't fooling anyone with her use of cosmetics and her attempts to attract a much younger suitor, and she should focus her thoughts on God rather than a husband. The crowd laughs uproariously at this, and Leonella is enraged. After reading Antonia's palm, the gypsy woman proclaims that this beautiful girl will be caught up in evil; she will love a main whose virtuous exterior hides a wicked heart.
Shaken, the two women return to their apartment to meet up with Elvira. However, the gypsy's prophecy is soon forgotten.
The novel begins by establishing the host of impulses (many having nothing to do with piety) that lead one to a house of worship. Though Ambrosio's wonderful sermons attract many listeners, many of the people have come to church to show off their finery, to find fault in Ambrosio's sermons, to gossip with neighbors, or to look at beautiful women. This sets the tone of the novel: even in houses of worship, intentions are not always pure.
Lewis first shows us the great Ambrosio, the central protagonist of the novel, through the admiring eyes of several people in his church. This literary technique establishes Ambrosio's respectability and public esteem more effectively than if the novel had begun from his perspective. Through the conversation between Lorenzo, Christoval, Leonella, and Antonia, the reader can see Ambrosio's unparalleled public stature, and his personal air of purity - which will make his fall from grace even more shocking.
Christoval's character is shaped by use of subtle but profoundly witty humor. Though a rather minor character in the novel, he stands in the tradition of the mischievous but loyal friend to the protagonist, similar to Mercutio from Romeo and Juliet.
Lorenzo, though something of a scoundrel (after all, he is trying to make moves on a woman in a church) demonstrates loyalty and courage - he is protective of his sister and quick to defend her. Additionally, his intentions towards Antonia involve marriage rather than merely a physical liaison.
The interpolation of the gypsy woman into the narrative is a peculiar one. Unlike any other character we have met thus far in the book, she speaks almost entirely in rhyme and meter, which suggests that her observations have a special weight. In describing an unknown but frightening fate awaiting Agnes, as well as Lorenzo's frightening dream in the church, the novel makes extensive use of foreshadowing to create an atmosphere of dread.