A couple sets up a video camera to discover what is making all that racket when they go to bed at night. That's really all you need to know. On a shoestring budget, director Oren Peli takes a simple premise and crafts one of the most effective films in the history of horror cinema purely by tweaking your expectations of what is lurking in the dark frame and letting viewers victimize themselves. You keep looking for something out of the ordinary—and when it finally comes, your pants will have been shat. Promise.