The impossible love between a minor young man and a nun. In 1944, in Marseille, Denis, a 14-year-old boy, finishes his 3rd year at a Jesuit college. During a visit to a patient in a hospital, he notices Sister Clotilde, a young nun who is not insensitive to her charm. Their friendship grows until the mother superior understands that it is evolving towards a feeling of love. Despite the advice of their respective entourage and imposed separation, they give in to their passion and eventually run away to spend the summer in Haute-Loire, in a property of the family of Sister Clotilde. When the Liberation arrives, the taboos and society catch up with them.