In 1999, 12-year-old Antoine Courtin accidentally kills a young neighbor boy. Panicked, he conceals the body and is never suspected of any connection to the child's disappearance. But the boy's death continues to haunt him, shaping his life in unseen ways. More than a decade later, Antoine is a young doctor with a fiancée and a promising future. On a rare trip home, Antoine thoughtlessly sleeps with a young woman from his past. She shows up pregnant at his doorstep a few months later, insisting that they marry, but Antoine refuses. Meanwhile, the newly discovered body of Antoine's childhood victim means that the case has been reopened. Then the young woman's father threatens Antoine with a paternity test --- which almost certainly would match the DNA found on the dead child's body.

Normally happy and well-adjusted Sophie Duguet doesn't understand what's happening to her: she has become forgetful and was even detained by the police for shoplifting --- a crime she has no memory whatsoever of having committed. As she slowly sinks deeper into dementia and depression, things go from troubling to alarming when she finds herself connected to the deaths of several people around her. In a desperate attempt to evade the law, a confused Sophie changes her name and relocates, hoping to outrun the demons now plaguing her. It soon becomes clear, however, that the real nightmare has only just begun.

Anne Forestier finds herself in the wrong place at the wrong time when she is trapped in the middle of a bank robbery. Shot three times, she is lucky to survive --- and morbidly unlucky to remember the face of her assailant. Followed home from her hospital bed, Anne is in grave danger. But one thing stands in her favor --- a dangerously vengeful partner, carrying the scars of devastating loss, who will break all the rules to protect the woman he loves: Commandant Camille Verhoeven.

Camille Verhoeven has reached an unusually content (for him) place in life. He is respected by his colleagues, and he and his lovely wife, Irene, are expecting their first child. But when a new murder case hits his desk --- a double torture-homicide so extreme that even the most seasoned officers are horrified --- Verhoeven is overcome with a sense of foreboding. As links emerge between the bloody set-piece and at least one past unsolved murder, it becomes clear that a calculating serial killer is at work.