Informed that his elderly father has mysteriously disappeared, anxious Parisian François (Amalric) recalls his tragic family history in Miller’s assured adaptation of the fact-based novel by Philippe Grimbert. As a sickly child, François instinctively knew that he was a disappointment to his champion swimmer mother and gymnast father. While he does find some solace in his friendship with kindly masseuse Louise, his discovery of a strange toy in the attic causes his parents to act more strangely towards him than ever. Louise eventually reveals to François that he once had a half-brother, and that his parents were not drawn together by fairytale romance but through violence and strife. Slowly but surely a terrible secret reveals itself and the family is violently torn asunder.
Georges (Daniel Auteuil), a television talk show host, and his wife Anne (Juliette Binoche), are living the perfect life of modern comfort and security. One day, their idyll is disrupted in the form of a mysterious videotape that appears on their doorstep. On it they are being filmed by a hidden camera from across the street with no clues as to who shot it, or why.
As more tapes arrive containing images that are disturbingly intimate and increasingly personal, Georges launches into an investigation of his own as to who is behind this. As he does so, secrets from his past are revealed, and the walls of security he and Anne have built around themselves begin to crumble.