In an intense tale of psychological terror, a social worker discovers a force of evil greater than she imagined possible when she attempts to rescue a mysteriously silent young girl.

Devoted family services specialist Emily Jenkins (Academy Award winner Renee Zellweger) has seen it all - lies, neglect, abuse - domestic horrors of every type. That is, until she takes on Case 39: The case of 10-year-old Lillith Sullivan (Jodelle Ferland) whose eerie, secretive family leaves Emily shaken and disturbed. When Lillith's parents attempt to harm their child in a lte-night ritual, Emily intervenes. Heartbroken by Lillith's loneliness and innocence, Emily decides to do something she has never allowed herself to do in the past: get personally involved. Hoping to do the right thing for the withdrawn girl, Emily offers Lillith a caring happy home until she can find an adoptive family.

That's when the real terror begins!