In a dramatic setup that recalls the opening act of Robert Wise's chiller Audrey Rose (1977), Sandrine Bonnaire (Monsieur Hire) stars as Claire, a mother terrified by the discovery that a strange woman has begun systematically following her little girl, locked within the grip of obsession. The woman, as it seems, has a complicated personal history with more ties to Claire's daughter than Claire initially realizes. In the mean time, we learn more about the other woman, Elsa (Catherine Frot) - a semi-imbalanced mother locked in a divorce battle for custody of her young son, who finds herself almost magnetically drawn to Claire's little girl after innocently glimpsing the child at a local birthday party. She's drawn not merely to observe, but to covet and ultimately possess, which sends Claire into a maelstrom of terror as she feels compelled to confront and contend with this threatening new presence, and to obtain an answer that will account for the woman's seemingly irrational behavior. Throughout the film, director Safy Nebbou plunges headfirst into a deceptively innocent and placid domestic realm of subdivisions, nursery schools and children's parks while subtly unveiling the potential for devastation that lies beneath all of it.