Paris fills the Académie Royale for Robert le Diable, with Levasseur returning as Bertram and the fashionable world arriving late as usual. Albert de Morcerf, Château-Renaud, Beauchamp, and Debray fill stalls and boxes while gossip runs faster than the music. Madame Danglars and Eugénie watch from Debray's ministerial box, and Morcerf is expected to join them after visiting the Venetian countess.
Albert tells the Venetian countess that a mystery horse named Vampa won the Jockey Club cup and that the owner must be Lord Ruthven, the strange Englishman from Rome. Château-Renaud insists the Count of Monte Cristo is the real sensation: unlimited credit, diamond horses, the rescue of Madame de Villefort, and now racing prizes scattered like coins.
At the end of the second act the Count enters his box with Haydée beside him. The young Greek woman, dressed in Eastern splendor and covered in diamonds, turns every opera glass toward her. In the Danglars box the baroness talks of six million francs and begs Morcerf to bring the Count to meet Eugénie. Eugénie herself is cold and curious about the beautiful stranger.
Albert leaves the Venetian countess to obey Madame Danglars's summons. The Count visits the Danglars box, thanks the baroness for the horses, and is introduced to mother and daughter. Madame Danglars asks whether he ever saw a more exquisite beauty than Haydée at the court of Ali Tepelini. Count Morcerf answers proudly that he was inspector-general of the pasha's troops and owes his fortune to that service.
Haydée hears the name Yanina and goes white as stone. She bends forward, then falls back with a faint cry while the whole theatre watches. The Count claims she is delicate and offers a drop from his phial, but in the box he whispers that Morcerf is the wretch who sold her father to the Turks for gold.
He leads Haydée out before the fourth act begins, having listened devoutly to the third as if nothing had happened and leaving before the fourth, as the Venetian countess later remarks with surprise. Paris has now seen the daughter of Ali Pasha beside the man who ruined her father, and the charge is no longer private. Opera night ends; exposure has begun.
Eugénie is the first unease in the house, before Haydée even sits down. Albert jokes that this chase-loving Diana, ringed by her nymphs, may yet turn him into Actaeon. Her beauty is decided, her brows habitually frowning, her manner too firm for the box that is trying to marry her off between acts. Debray's ministerial box holds Madame Danglars and that daughter. The Venetian countess holds the gossip about a horse named Vampa and a cup sent by a man she has never met.
The Greek woman ends the guessing. Diamonds, Eastern dress, every glass in the house turned toward the Count's box. Albert crosses to obey Madame Danglars and meets the Count coming out. In the box, six million francs are still the baroness's idea of conversation, until she asks Morcerf whether Ali Pasha's court ever showed him a beauty to match Haydée. He answers as the inspector-general of the pasha's troops, the man whose fortune began there. Haydée hears Yanina and goes white. The faint is public. The whisper is not. Morcerf sold her father. The Count takes her out before the fourth act, and Paris has watched the daughter identify the traitor without a speech.
