Marguerite returns to her chamber distraught and tells Damienne that Roberval will take her with him to New France. Damienne insists this is wrong and impossible, but ultimately accepts the truth. Marguerite resolves to find Damienne a safe place to remain in France, but Damienne refuses, having promised Marguerite's dying mother she would never leave her. They must go together.

The next morning, Marguerite seeks out Alys and asks her to arrange for her sweetheart Jean to ride to Périgord with a letter. Marguerite gives Alys gold and writes secretly under the pretext of copying psalm arguments, since Damienne cannot read. The letter, addressed to Madame D'Artois, begs her to intercede with Madame Montfort to take Marguerite and Damienne back. She seals it with Claire's ring bearing the initial M and gives it to Alys before dawn.

That afternoon, Marie summons Marguerite to Roberval. Frightened, Marguerite descends with her psalter to find Roberval waiting silently. He makes her read verses about the wicked and divine punishment, then reveals her opened, broken-sealed letter from his cabinet. He confronts her, calling her a liar, warning her never to confide in servants, and forces her to continue the lesson while her exposed letter lies between them. Marguerite realizes he enjoys hunting and possessing her; she is sport.

Dismissed, Marguerite encounters the maids returning with laundry and chases Alys into the storeroom, where she beats her about the head with the psalter. Alys claims Roberval seized the letter from her, but Marguerite does not believe her. Spent and ashamed, Marguerite returns to Damienne, who already knows of the betrayal—the whole household knows. Damienne gently rebukes her for trusting Alys, who must serve her master, but Marguerite insists she had no choice and vows she will not let Damienne die aboard Roberval's ship. Damienne replies she fears only for Marguerite.