Rose Keller, 35, is replacing primary schools. During a mission lasting a few weeks, she meets 8-year-old Lisa, one of her particularly endearing students. Rose quickly realizes that Lisa is being abused in her home, and that she is in danger of death if no one does anything. Faced with the helplessness of social services, she decides to kidnap the little girl. Wanted by the police and by Lisa's biological mother, Rose has no other solution than to take refuge with her own adoptive mother.