In the late 18th century, Marianne, a talented artist, is commissioned to paint the wedding portrait of Héloïse, a young woman from an aristocratic family who is betrothed to a Milanese nobleman. Héloïse, however, is strongly opposed to the marriage and has refused to pose for previous painters. Marianne is introduced as a hired companion to accompany Héloïse on her daily walks, secretly observing her to capture her likeness and paint her in secret. As the days progress, Marianne and Héloïse begin to develop a deep and complex bond that transcends the initial pretext of the painting.

Marianne’s covert task becomes increasingly challenging as her feelings for Héloïse grow more profound. As they spend more time together, the two women discover a shared sense of understanding and mutual admiration. This intense connection allows Marianne to see Héloïse in a way no one else has, which enriches her artwork but also complicates their relationship. Their time together creates an intimate space where both women confront their desires, identities, and limitations imposed by society.