Mrs. Géquil is a 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 be able to keep the powerful and dangerous Mrs. Hyde contained?
Set against the background of a brutal crime gang in Brussels, a tragic love story between Gigi (Matthias Schoenaerts), a high-flying gangster, and Bibi (Adèle Exarchopoulos), a young racing driver with very upper-class roots.