In 1950s rural France, Gabrielle (Marion Cotillard) is a fiercely romantic woman whose uninhibited desires and obsessive infatuations alarm her conservative family. To curb her erratic behavior, her mother forces her into an arranged marriage with José (Àlex Brendemühl), a gentle Spanish bricklayer. Gabrielle openly declares she does not love him and refuses physical intimacy, yet José remains devoted and patient. When Gabrielle is sent to a thermal spa in the Swiss Alps to treat painful kidney stones, she meets André Sauvage (Louis Garrel), a gravely ill, melancholic war veteran. Captivated by his sensitivity and shared love of music, Gabrielle embarks on a passionate, secret romantic and sexual affair with André, believing she has finally found her true soulmate—only for a devastating twist to reveal the boundary between reality and her own psychological projection.