Emily Jenkins is a dedicated social worker overwhelmed by her caseload in Oregon. She's assigned to investigate the family of Lillith Sullivan, a quiet and withdrawn ten-year-old girl who shows signs of severe abuse. Despite encountering initial resistance from Lillith's parents, Emily discovers a horrifying attempt by them to harm Lillith. With help from Detective Mike Barron, Emily intervenes just in time to save Lillith and gains temporary custody of her. Convinced she's rescuing an innocent girl from a tragic situation, Emily begins to feel a deep sense of responsibility and care for her, even arranging for Lillith to stay in her own home.

As Emily tries to provide a safe environment for Lillith, strange and unsettling events begin to occur, raising questions about the true nature of the girl she has taken under her wing. Emily witnesses increasingly disturbing incidents that make her question her own judgment and sanity. Her life and relationships begin to unravel as the sinister mysteries surrounding Lillith's past and true identity come to light. The once-clear lines between victim and villain blur, leading Emily down a dark and dangerous path as she seeks to uncover the truth and protect herself from a malignant force she never anticipated.