After taking leave of Monte Cristo, Maximilian goes to see Valentine and Noirtier. He finds Valentine feeling ill and complaining that all drinks taste bitter to her. Their meeting is interrupted when Madame Danglars and Eugénie arrive, announcing that Eugénie will marry Andrea Cavalcanti in one week. Eugénie expresses her displeasure at being chained to a man rather than being allowed to live as an independent artist. Feeling progressively sicker, Valentine excuses herself and returns to Maximilian and Noirtier. While with them, she loses consciousness.
Maximilian runs to Monte Cristo and begs for help. Monte Cristo is indifferent to Valentine’s plight at first, but when he hears that Maximilian loves her, he promises that he will save her life. Back in the Villefort home, the doctor communicates with Noirtier, who seems to understand what has happened. Noirtier confirms that Valentine, like all the others, has been poisoned. The only reason she is still alive is because he has slowly been accustoming her to successively larger doses of brucine, knowing that she would be the next victim. As the doctor goes to examine Valentine, Monte Cristo rents the house next door to Villefort’s in the guise of the Abbé Busoni.
Earlier that day, Eugénie confronts Danglars and declares that she will not marry Andrea Cavalcanti. Danglars confides in her that he is on the brink of financial ruin and that he needs the three million francs that his daughter’s marriage with Cavalcanti will bring. Public knowledge that he will soon have this money at his disposal will be enough to restore his credit and allow him to borrow money in order to speculate in American railroads.
Eugénie agrees to go through with the signing of the marriage contract on the condition that her father merely use the report of the three million to restore his credit and not actually use any of Cavalcanti’s money. Eugénie hints that there is a dramatic reason for her request, but Danglars loses all curiosity once he is assured that she will sign the marriage contract and thus ensure the return of his credit.
Three days later, a large party at the Danglars’ residence celebrates the signing of the marriage contract. Just as the contract is being signed, Monte Cristo announces the existence of the letter written to Danglars by Caderousse. Monte Cristo claims that the letter has been found that very day in Caderousse’s vest and that it has since been given to Villefort. He does not reveal the content of the letter, but as he finishes speaking, two gendarmes appear, looking to arrest Cavalcanti. Andrea (Benedetto in disguise), however, has disappeared.
As the guests leave, Eugénie rushes to her room with Louise d’Armilly. The two women discuss their disdain for men and their plot to run away together to Italy by way of Belgium. Once in Italy, they plan to make a living from their music. They decide to leave that night. To prevent detection, Eugénie will dress as a man and pretend to be Louise’s brother. Though Louise is frightened, Eugénie is fearless and doubtless. She cuts her hair and triumphantly dons masculine clothes. The two women pile their possessions into a carriage and ride away.