Marc, a literature professor in his 40s at the University of Lausanne, remains unmarried and resides with his sister Marianne in a large, secluded chalet they inherited as children. He frequently engages in romantic relationships with his students. As winter draws to a close, one of his brightest students, Barbara, mysteriously vanishes. A couple of days later, Marc encounters Barbara’s mother, Anna, who is eager to learn more about her missing daughter.