Marie-Pierre lives with Suzanne, her mother's lawyer, since her father left them for another continent. Suzanne's job requires her to work long hours in the office, so Marie-Pierre is more often than not alone at home. As a responsible and independent girl, Marie-Pierre occupies her evenings doing her homework, sometimes with her friend Loulou with whom she shares everything. For some time now, she has been receiving anonymous calls that worry her and she sees a strange activity in her room. Personal items disappear unexplained. Not wanting to worry her overworked mother, Marie-Pierre, Loulou and their friend David try to shed light on these mysterious events. Would it be Leveille, the insolent schoolboy, and his gang who are having fun scaring her?