Based on his own short film, David F. Sandberg’s feature-length debut has a wonderfully simple central premise: fear the monster that lurks in the dark. Though it occasionally gets bogged down in an on-the-nose screenplay, Lights Out is an otherwise quite relentless horror flick that plays on basic childhood terrors with efficiency. Lights Out opens with a near beat-for-beat recreation of the short, albeit in the gloomy textile factory workplace of Paul (Billy Burke).