He never thought to ask the family he bought the box from about it?

I thought for sure there was going to be a scene where he brings the box back and freaks the old lady out again. But Clyde doesn't even think to ask.

That's just one little nitpick. That, plus wouldn't the demon WANT the box to be destroyed so it could be free? Other than that, I thought this was pretty good. The girl's acting and cinematography were solid.