From the liner notes

French director Marina de Van follows her boldly audacious debut In My Skin with the thriller Don't Look Back, another brave, disturbing plunge into darkness that plays with identity and body doubles a la David Lynch's Mulholland Drive and David Cronenberg's Dead Ringers.

Jeanne (Sophie Marceau)—a writer, married, with two children—starts to see unsettling changes in her home. Her body is beginning to change. No one around her seems to notice. Her family dismisses these fears as the result of stress related to finishing her next book, but Jeanne realizes that something far deeper, far more disturbing is taking place. A photograph at her mother's house sends her in search of a woman in Italy. Once there, Jeanne morphs into an entirely different person known as Rosa Maria (Monica Bellucci) and embarks on a determined quest to uncover the secret hidden in her past that has undermined her world.