Devoted family services specialist Emily Jenkins 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, whose eerie, secretive family leaves Emily shaken and disturbed. When Lillith's parents attempt to harm their only child in a late-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 Hoping to do the right thing for the withdrawn girl, Emily offers Lillith a caring, happy home until she can find an adoptive family.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.