The successful documentary filmmaker Jean travels to Paris. He lets friends and family believe that he has gone to Brazil. But in truth, he begins an investigation. In apartments, cafés, and streets, he searches for clues and relics of a woman who has never left his mind. Years earlier, he had first encountered her and her husband Rigaud on the Côte d'Azur. Later, they met again in Paris, and a few years after that, Jean learned of her suicide in a hotel in Milan. Now in Paris, he moves into an apartment he believes Ingrid shared with Rigaud. He starts to document Ingrid's story based on tiny details, capturing all her disparate elements that are held together by an invisible thread, a thread that threatens to snap and is referred to as the course of a life.