The first trailer for David F. Sandberg’s Lights Out introduced Diana, the creepy dead woman who lives in darkness, haunting a family connected to her past. The new trailer goes a little more in depth on this unfortunate family curse that supremely legitimizes anyone who has ever been afraid of the dark. And, as with all successful horror movies, a young child is involved. Based on Sandberg’s short film of the same name, Lights Out is about Rebecca (Teresa Palmer), a young woman who sees a terrifying being whenever the lights are off. Her little brother sees the shadow-figure, too, and gathers that her name is Diana. Who is Diana, and why is she lurking in darkness like a freak? Doesn’t Diana know that’s scary as shit?!

Rebecca’s mother, played by Maria Bello, might have answers. As a child, she had a friend named Diana who, according to the flashback footage, has always had a kind of “I will haunt you to the end of the world” kind of vibe. Something terrible happened to her—a medical experiment gone wrong, from what it looks like. And now, mom seems pretty chill about the fact that her friend is back in ghoul form, tormenting her children. She’s all “keep the lights out.” No, mom! The trailer, full of familiar but still terrifying horror imagery, is enough to make one reconsider sleeping with the lights off.

Lights Out is produced by James Wan, director of the Insidious and The Conjuring films. It will hit alarmingly dark theaters on July 22.