Director David F. Sandberg expands a 2-1/2 minute short to feature length, telling the story of a Los Angeles family—mentally ill widowed mother Sophie (Maria Bello) and her two children, Rebecca (Teresa Palmer) and Martin (Gabriel Bateman)—tormented by a malevolent entity that can only take physical form in the dark. Sandberg does his best to maximize his creepy premise, including finding as many creative ways as possible for the protagonists to generate light when threatened. But he’s ultimately undone by the need to create a detailed back-story for his shadowy ghost and the troubled humans, and the mythology doesn’t have much internally-consistent logic. The attempt to include actual character arcs may be admirable—and the casting of Bello and Palmer as mother and daughter is perfect—but they just don’t entirely work, nor are the scares scary enough when the “rules” of the monster keep shifting and the heroes don’t seem smart enough to make optimum use of their one known advantage. Sometimes a mysteriously unsettling 2-1/2 minute concept should just remain as a mysteriously unsettling 2-1/2 minute concept. By Scott Renshaw