Set in the rural countryside of post-World War II France, the story is a memoir of a young girl, Elisabeth, who lives with her family in a large, stone house on the grounds of an insane asylum. Her older sister Agnes has just left for boarding school, leaving Elisabeth alone in the old house full of shadows and dark corners. Her father is absorbed in his work; her mother, an unwilling housewife, spends most of her spare time doing various "errands" in the city, and Elisabeth is left in the care of Rose, the simple, almost dumb maid. One day she comes upon Yvon, an escapee from the asylum, hiding trembling in the bushes. Moved by his frailness, Elisabeth hides him inside the bicycle shed. As police search for the potentially dangerous inmate, the two form a bond. Yvon's mute innocence and frailty stand in stark contrast to her parents' severity and emotional distance and, despite the lurking threat, Yvon proves to be an innocent monster--an infant trapped in the body of a man.