Lucie and Marie are twin sisters with a love-hate relationship, their personalities completely opposed. Lucie is an extroverted pin-up model, while Marie is a quiet, reserved model of austerity. One day, when Lucie is offered an exclusive recording contract despite the fact that she cannot sing, Marie, who possesses a good singing voice, goes to Paris to perform in place of her sister. When Marie returns to Lucie, she finds Lucie has committed suicide, and she has no choice but to assume Lucie's name. But as she spirals uncontrollably further downward into Lucie's dark life, she finds a hidden side of herself.