Drama 8-year-old Nelly (Joséphine Sanz) has just lost her grandmother. While helping her parents, she explores the surroundings of the house where her mother, Marion, used to play as a child. There she discovers the treehouse she’s heard so much about. One day her mother abruptly leaves. Nelly meets a girl her own age in the woods and together they set about building a treehouse. Her new friend is called Marion (Gabrielle Sanz).