Two policewomen from Internal Affairs arrive in a provincial precinct to investigate the death of an Algerian woman who was an informer. One punches, the other eyes, tip top.

Mrs. Géquil is an eccentric teacher despised by her colleagues and students. On a stormy night, she is struck by lightning and faints. When she wakes up, she feels different. Will she now be able to keep the powerful and dangerous Mrs. Hyde contained?