Marguerite, the nine-year-old narrator, introduces her circumstances: her mother died giving birth to her, leaving only a name and a ruby ring; her father died fighting for the King at Pavia when she was three. Orphaned, she is heir to a wealthy château in Périgord with vineyards, villages, and lands, but is alone except for servants. Her elderly nurse, Damienne, has raised her since infancy, teaching her prayers, manners, and stories of her noble parents.

Marguerite is a curious, willful child who climbs towers, runs to the stables, and resists Damienne's discipline. Damienne combs lice from her hair, scolds her ruined slippers, and dresses her in silver and pearls because her guardian has come to visit for the first time.

The guardian, Jean-François de la Rocque de Roberval, is Marguerite's father's cousin, a famous voyager and the King's boyhood friend. He receives Marguerite in her own great hall with an air of ownership, examining her dispassionately. Marguerite is enchanted by an ebony cabinet on his table, full of compartments and secret drawers. Roberval shows her a drawer brimming with gold écus and gives Damienne coins for Marguerite's clothes and lessons. He questions her about reading, writing, and music, finding her uneducated, and tells her to learn her book.

Marguerite secretly hopes he will give her the cabinet, but he simply dismisses her. Back in their apartments, Damienne reveals her relief: Roberval is leaving at dawn to go to sea, meaning he will not separate them. Marguerite, not grasping the threat, teases Damienne for her trembling. Together they count the gold coins, planning new gowns, a caged bird, a virginal, a trousseau chest, and tutors who will teach Marguerite to read, write, and play music.