The Durras family lives in the House of the Bories, an isolated country villa in Haute-Provence. Julien Durras, a university geologist, dedicates himself to his research, and is strict with both his children and his young wife Isabelle. The Durras household is greatly affected by the arrival of a young German scholar, Carl-Stéphane Kursdedt, whom Julien invited to his house to translate his papers. The children take an instant liking to the friendly young German, who plays with them and gives them presents. Isabelle also finds herself drawn to Carl-Stéphane and, before they know it, their friendship is drifting towards romance. When Julien is away for a few days, Isabelle discovers that she is in love with her young guest and is tempted to spend the night with him...