Emilyis a somewhat idealistic woman. She is still single. She has a boyfriend who is a psychologist. Live alone in a large two-story house. She works in a child welfare agency, and her daily job is to help children who suffer from domestic violence escape from the sea of misery, and to deprive their irresponsible parents of custody by the law. During this time, Emily was very busy, with 38 cases to deal with, but his boss assigned Case39 to her. The "victim" of Case39 is a little girl, Lily, beautiful and well-behaved, but her parents are always plotting to kill her. One night Emily received a call from Lily. Lily said that her parents were going to kill her. Emily rushed to Lily's house desperately and rescued the overly frightened Lily from the oven.
Lily and Emily, who started a new life, live together. At first they looked like good mothers and daughters who were intimate, but things were far less peaceful than they seemed. There was a problem with a case in Emily's hands. A little boy killed his parents. Phone records show that he had received a call from Emily's house the night before he killed his parents. But Emily never called, and Lily denied it. When Emily came to the prison to ask the little boy's phone question, the little boy suddenly died, and Emily was haunted by suspicious groups one by one. Not long after, Emily’s psychology boyfriend also received a call from Emily’s mobile phone, and soon he also self-harmed and died in the bathroom. After checking the phone recordings, Emily discovered that Lily was not an ordinary girl. She was possessed by the devil and was the spokesperson of the devil. So she tried every means to kill Lily, just as Lily's parents did. But Lily has good intuition and perception. She can also control people's thinking. To kill her, she must first defeat her fear. Those who died before, without exception, died of the illusion that Lily had planted in their minds.
