Renée Zellweger plays Emily, a single woman who works as a social worker. She has already worked on 38 cases when her boss gives her one more file. This is why this movie is called case 39. A 10 year-old girl, Lily, in the last 3 months has been got bad marks at school, sleeping in the class-room, and has no friends. Emily suspects that she is abused by her parents at home. When she visit them, the parents do show strange behaviour. She keeps an eye on Lily, until one night when she finally saves her when her parents are about to kill her by putting her in the oven. The parents go to mental institution and Lily stays with Emily. However it turns out that Lily's parents are not crazy and that they wanted to kill the little girl because she is very dangerous.
Like Omen - but not as scary - the child is the devil incarnation. In Emily's world, where most of the people don't believe in God, the only way to get rid of the child is to kill her. It's not easy for me to grasp: if one doesn't believe in God, how can one believe the existence of devil? -even though if one sees it with one's own eyes. Emily suffers because she sees her friends die one by one, even more suffers because she knows she is the indirect cause of their deaths because she has taken Lily under her wings.