Pediatric Alex Beck (Francois Cluzet), still devastated by the savage murder of his wife Margot (Marie-Josee Croze) in the early days of their marriage eight years ago, receives an anonymous email. When he clicks on the link he sees a woman's face standing in a crowd and being filmed in real time - Margot's face. Is she still alive? And why does she instruct him to "tell no one"?