The night of the ball at Fernand’s house is hot and stuffy because the party occurs in the middle of July. The guests arrive promptly despite the heat, and though the count wipes his brow to rid it of beads of sweat, he refuses the iced drinks Mercedes’s servants offer him. When the count wonders why the blinds are lowered, Mercedes, who remains focused on him and his intentions, orders that the windows be cleared of all impediments to allow a cooling breeze to waft through the house. Mercedes then invites the count to walk with her through her garden. She is extremely curious about the count and has asked her son many questions about him. Now is her chance to get to know him better, she thinks.

Mercedes takes the count into a large greenhouse. As they pass vines and trees normally grown in more southern climates, Mercedes tries to get the count to eat some grapes. He refuses. She offers him a peach, and still he refuses to eat. She then mentions that a sign of friendship is when two people share food under the same roof. Although the count acknowledges that he is aware of this sentiment, he tells her that he does not want to partake of any food or drink. Mercedes feels very sad that the count is standoffish with her. She wants to become more involved with him, though it is not explained why. It is not clear if she has recognized him or if she merely senses a familiarity when she is near him. It is not clear how the count feels about Mercedes at this point, though he does become slightly rattled when he sees her. But the count identifies Fernand as an enemy, so he does not let his guard down and despite whatever he might feel for Mercedes, the count continues to refuse to eat while at Fernand’s house.

As Mercedes and the count are about to continue their walk, Albert comes to his mother to announce that M. de Saint-Meran, Valentine’s maternal grandfather, has died. Madame Villefort and Valentine must leave the party, and the news puts a somber mood on the ball.

The scene changes to the office of Valentine’s father. Villefort had remained at home and is in his office, still trying to figure out how the count has gained so much intimate information about him. Madame de Saint-Meran enters Villefort’s study. She tells her former son-in-law of the death of her husband, which occurred quite suddenly and unexpectedly. Madame de Saint-Meran is very faint, and Villefort suggests that she go to bed. He will send Valentine to her as soon as his daughter returns home.

When Valentine enters her grandmother’s room, she is shocked by her grandmother’s pale countenance but is also disappointed that the elder woman insists that Valentine go forward with her proposed marriage. Valentine’s grandmother wants to meet Franz as soon as possible because she is quite sure that she, too, is about to die. She has seen an apparition of her deceased husband and is convinced her that her own death is imminent. She also asks for a notary so she can ensure that Valentine inherits her entire fortune.

After making sure that her grandmother is comfortable, Valentine escapes to the back garden, hoping to find Maximilian at the gate. He has been waiting for her. Valentine tells him that she must marry Franz because of her allegiance to her father and her grandmother. Maximilian encourages Valentine to run away with him, but she refuses. When she asks what Maximilian will do if she marries Franz, the young man tells her that he will end his life. Unable to bear this, Valentine promises she will do everything she can to get out of marrying Franz.

Two days pass, and Maximilian finally receives a note from Valentine telling him to meet her at the back gate. Her father has invited Franz to their house to sign the contract papers for marriage. Maximilian will help Valentine climb the back fence and they will run away together.

Maximilian is at the back gate before the appointed time. He waits patiently, but Valentine does not appear. It is well into the night when he becomes desperate and climbs the gate to investigate what might be happening inside the house. He is forced to hide when two gentlemen come into the garden. He soon discovers the men are Villefort and a doctor. Maximilian overhears them discuss the death of Valentine’s grandmother. The doctor tells Villefort that he suspects the woman has been poisoned but promises not to tell anyone.

Maximilian later sneaks into the house and finds Valentine. She takes him to meet Noirtier, her paternal grandfather. Noitier tells them (by blinking to Valentine) that he will help them. They are not to run away. He will take care of the details. This is hard for Maximilian to accept because the old man is completely paralyzed and cannot speak, but he promises to obey.

After the combined funeral of Valentine’s maternal grandparents, Villefort invites Franz to his home. He tells the young man that he wants to offer him his daughter in marriage. Franz accepts. A meeting is planned for a half-hour later, when the contract papers will be signed. When Valentine, Franz, the Villeforts, a notary, and several witnesses are assembled when there is a knock on the door. Noitier’s servant announces that Noirtier wants to speak to Franz.

Everyone is amazed, including Valentine. She wonders if her grandfather can really mean to speak and how he can do this. She runs ahead of Franz so she will be the first in the room. Franz and the notary follow.