François Seurel, the 15-year-old narrator of the book, is the son of M. Seurel, who is the director of the mixed-ages school in a small village in the Sologne, a region of lakes and sandy forests in the heartland of France. François is intrigued when 17-year-old Augustin Meaulnes, a bright young man from a modest background arrives at the school. Because of his tallness, Augustin acquires the nickname "grand". He becomes a hero figure to the class and runs away one evening on an escapade where, after having become lost, he chances on a magical costume party where he is enchanted by the girl of his dreams, Yvonne de Galais, a character inspired by the real-life Yvonne de Quiévrecourt. She lives with her widowed father and her somewhat odd brother Frantz in a vast and ancient family château – Les Sablonnières – which has seen better days. The party was being held to welcome Frantz and the girl he was to marry, Valentine. However when she does not appear, Frantz attempts suicide but fails.