Act 3
Chevreuse’s residence
Chevreuse, who was only slightly wounded in the duel, tells Maria and Chalais that he will arrange to have Chalais escape from the city. Chalais leaves, and again, everything looks good at first, but disaster strikes. Chalais’ letter and Maria's portrait, hidden in Chalais's desk, are discovered by one of the courtiers. Chalais tells Maria about the letters and she says all is lost. Once again she tells him to flee through a secret passage, and he does, but tells her he will return if she does not follow him within an hour. Maria sings a prayer, Havvi un Dio che in sua clemenza.
The courtier gives the letter and portrait to Chevreuse and he is alternatively nostalgic and enraged. He confronts Maria and vows revenge. Suddenly Chalais returns for Maria through the secret passage. In a final trio Maria pleads for Chevreuse to kill her, Chalais says he doesn't fear death, and Chevreuse thunders that Chalais’s death is imminent. He gives Chalais a dueling pistol and the two race out. A shot is heard. Chevreuse returns and says Chalais has committed suicide. He throws the letter and portrait to the floor before Maria and cries out La morte a lui . . .La vita coll’infamia A te, donna infedel / "For him, death . . . For you, life with infamy, faithless woman".
Note: Donizetti wrote a culminating cabaletta for Maria, but crossed it out, preferring to end the opera in a distinctly non-bel canto, but highly dramatic manner.
