When it comes to horror movies, there isn’t a whole lot that we haven’t seen: mask-wearing killers, extraterrestrial life, monsters that take on every form imaginable, paranormal activity, witches that lurk in the woods, possessed dolls — inexplicable, albeit obvious terrors that are expected to strike fear. But a smile? The universal expression that, for the most part, indicates happiness, joy, and amusement, and in turn, evokes calm and ease in others? Not exactly horror material — until now.