Sara leads a double life: the up-front one, where she plays the role of a good and diligent girl apparently without problems, and a secret one, made up of constraints, self-discipline, and strict rules to force an unattainable ideal weight on her body.
In the beginning, nobody seems to notice anything wrong: neither her parents nor her close friends realize the evolution of her disease. Sara manages to conceal her habits: forced food abstinence, runs in the park up to exhaustion, hours and hours spent training at the gym, lunches and dinners cleverly hidden in the trash container in front of her house. At the same time, Sara builds her "room of secrets” in a self-storage building, where, with some furniture taken from her old house, she creates a lounge where she can relax and act undisturbed. As Sara loses weight, she feels stronger and stronger, more and more powerful and invincible. Everything seems to proceed smoothly until the girl faints during a school trip. Henceforth, her problems with food, which have remained invisible till then, become evident to everybody.