Brittany, France, 1770. Marianne is a painter who has been hired to paint the marriage portrait of Héloïse, a young woman who has just left the convent. Héloïse does not accept her fate as a married woman and refuses to pose, so Marianne must work in secret. To do this, she pretends to be a lady-in-waiting in order to observe her by day and paint her at night. Their relationship grows more intense as together they share Héloïse’s last moments of freedom before her wedding.