Based on Herman Melville’s novel Pierre; or, The Ambiguities, the film follows Pierre, a successful young novelist living a charmed, aristocratic life in a French château with his beautiful mother, Marie. He is engaged to the lovely Lucie and seems to have a perfect future ahead of him. However, his reality is shattered when he encounters a mysterious, ragged woman named Isabelle in the woods. She claims to be his long-lost half-sister, born from a secret affair his father had years ago. Consumed by a need for "truth" and justice, Pierre abandons his mother, his fiancée, and his wealth to live in poverty with Isabelle. Their relationship quickly spirals into a dark, claustrophobic, and increasingly incestuous obsession as they hide away in a bohemian warehouse in Paris.