Alfonso and Lucrezia depart from the villa, heading toward the castello in Ferrara together at last. Throngs of people await them at the castello, and the noise of the celebration is overwhelming and discordant.

Inside the castello, Alfonso introduces Lucrezia to his sisters, Elisabetta and Nunciata. Elisabetta is poised, gracious, and seemingly welcoming, but Nunciata is abrasive and skeptical. Elisabetta remarks that Lucrezia is lovely, while Nunciata only notes that she is young. Lucrezia, uncomfortable, realizes that Nunciata is specifically referring to her likely fertility and that the family is collectively and expectantly awaiting an heir.

Inquiring about whether she might also meet their mother on this visit, Lucrezia inadvertently instigates an argument among the three of them. She had assumed the “satisfactory resolution” Alfonso referenced earlier meant that the problem had been avoided, and she has now embarrassed and upset him.

Diverting the conversation, Elisabetta insists on showing Lucrezia to her chambers. The sisters take her upstairs, and during the conversation Nunciata references a romantic indiscretion on Elisabetta’s part. Elisabetta, embarrassed and seemingly shaken, insists that Lucrezia keep this to herself. Lucrezia agrees, noting that the mood between the sisters has dramatically shifted: Nunciata has clearly exercised an unspoken power over Elisabetta by bringing up this confidential information.

The sisters ask if Lucrezia has ladies-in-waiting and are surprised to learn she has only a maid. Nunciata promises to appoint someone, telling Lucrezia that a lady-in-waiting can also help her update her wardrobe appropriately. The conversation shifts toward Alfonso, and Lucrezia senses a tentative quality in Elisabetta’s questions. She asks if he is attentive to her but also if he is kind. Lucrezia, uneasy, says yes. They bid her goodnight, noting that Alfonso’s apartment is directly below her own and that the two connect with a staircase. Lucrezia, unable to sleep, lies awake until nearly morning.

They hold a celebratory banquet, for which Alfonso has ordered special singers from Rome. They are extraordinary, and Lucrezia has never heard anything like them before. As she watches her husband watch the singers, she is moved by the depth and intensity with which he listens. Most of the partygoers simply enjoy the music while chatting amongst themselves, but Lucrezia and Alfonso are both transfixed.

Pondering how to convey the luxury and fashion of this event in her next letter to Isabella, who would surely be envious, Lucrezia asks Alfonso how the singers manage such remarkable vocal shifts. They’re evirati, he tells her, men who are castrated at a young age to maintain their vocal chords. Shocked, Lucrezia wonders whether they had a choice in the matter. As the music continues, Alfonso takes her hand as they sit together—a gesture that, in public, is deeply significant and indicative of his love for her.

Across the room, Lucrezia notices something shocking. Elisabetta has just walked by a guardsman without looking at him, but he handed her a note that she quickly tucked up her sleeve. Nobody else, Lucrezia realizes, seems to have noticed, and Elisabetta has taken on a faint glow. Struggling to sleep again that night, Lucrezia begins a tender painting of a couple, seemingly happy and serene. Before anyone sees it, she covers it with paint to erase it again.

Alfonso is busy at the castello, which suits Lucrezia very well, but her leisure time is soon co-opted by Elisabetta and Nunciata, both of whom seem eager to be in her good graces. They appoint her a lady-in-waiting named Clelia, who begins to rework Lucrezia’s style to fit the Ferrarese court.

When Lucrezia writes to her mother, noting the attentions of the sisters, she receives a warning that stuns her: do not be fooled by this false affection; your favor is too valuable for them to ignore. Unsure whether to trust the sisters or to heed this warning, Lucrezia hides the letter in a drawer. Alfonso, too, is skeptical of the sisters’ influence on Lucrezia, interrogating her about her relationship with them when he notices that her new hairstyle looks like Elisabetta’s.

Sittings for the portrait resume, and Il Bastianino and Maurizio start work on the portrait. Posed by a window, Lucrezia notices Elisabetta and her guardsman, Ercole Contrari, having a secret rendezvous on a battlement in the distance. Alfonso wanders toward the window and looks out, and Lucrezia is relieved to see that Elisabetta has gone by the time he gets there.

Alfonso sends for a special dress for the next sitting. Lucrezia dislikes it but is pleased to see Jacopo return to work on the project. He won’t look at her, she notices, only at the parts of the dress he is asked to render. As the portrait takes shape, Lucrezia hears Alfonso say to himself, perplexingly, “there she is, my first duchess.” Surely he must have meant something else, she tells herself—perhaps “beautiful.”

Jacopo drops his pencil, and it rolls toward Lucrezia’s foot. For the first time, she hears him speak: he says “clumsy idiot,” to himself, in the Neapolitan dialect. “You are from Naples?” she asks him quietly, and he is startled to hear the language spoken back to him. “I shall never forget that you saved my life,” he tells her. 

Waking one night to hear a violent screaming, Lucrezia steps outside to hear more clearly. Terrified, she realizes a woman is begging Alfonso for mercy. Unsure what is happening, she is surprised the next day to receive a message that she is to remain in her rooms until further notice.

Disregarding the message, Lucrezia goes downstairs to confront Alfonso. She tries to inquire about the noises, noting that there is no sign of Elisabetta in the castello, but he sends her away angrily. Jacopo is present for this interaction, but Alfonso behaves as though they are alone. He thinks, Lucrezia realizes, that Jacopo is deaf and can’t hear him threatening her.

Returning to her room, Lucrezia looks out the window and sees a coffin being carried over the bridge. Emilia tells her the awful truth: upon discovering Elisabetta’s relationship with Contrari, Alfonso killed him and made Elisabetta watch.

Lucrezia sneaks to Elisabetta’s room and finds her in a rapidly deteriorating state. Elisabetta accuses Lucrezia of having told Alfonso but accepts her denial. Instead, she warns Lucrezia: when the two of them are unable to conceive, Lucrezia will be the one who is blamed. Terrified, Lucrezia goes to her chamber and locks the door, longing to return home to Florence. 

She remains locked inside until receiving word that Alfonso and Leonello Baldassare have left for Modena, at which point she begins to wander the grounds. Finally, she writes a letter home. It reads, with desperation: “I no longer feel safe in this place.” Sure that she will soon be rescued by her family, Lucrezia makes plans to return to Florence. 

Reading her mother’s response, Lucrezia’s hopes are dashed. Her mother tells her to rein in her imagination and focus on conceiving an heir.