A young woman (Teresa Palmer) must protect her brother (Gabriel Bateman) from a terrifying apparition that only manifests in total darkness. Later, she realizes that this fearsome entity is connected to her mentally ill mother (Maria Bello), who has started hallucinating conversations with a mysterious figure named Diana. Billy Burke and Alexander DiPersia co-star. Produced by James Wan (The Conjuring), Lights Out is a feature-length expansion of director David F. Sandberg's short film of the same name, which became a viral sensation online.