In a castle, isolated in the heart of winter, lives a strange family: Hugo, in his forties; Eléonore, his wife; Aunt Agathe, Hugo's sister, an old maid attached to traditions; Sébastien, Eléonore's brother, to whom he is devoted with a troubled affection. Frédéric, a young student, is welcomed by the family and stays at the castle for a while to research a family ancestor. A complex game of manipulation then begins, orchestrated by all the family members, during which Frédéric finds love, at the risk of his life...