You check it before the movie. There's also a nice spoiler protected synopsis that explains what happened while you were gone, but it doesn't show unless you click the link. So what it does is, it gives you cues on when you can leave that are fairly safe (Example cue from We're the Millers: ), and if you use them, you check them while you're outside to see what you missed (if you're fairly spoiler-paranoid like I am). The thing to do is, check a movie you've already seen, or that you're fairly sure you won't see.