Who expected a movie with a title like this to be any good? Despite some confusion as to how the logic of this actually worked, it was fantastic. It genuinely creeped me out at spots (something I totally didn't expect). I was assuming it would be something akin to The Blob or maybe The Evil Clowns From Outer Space or whatever that movie's called... But this was a very intelligent, wonderfully dark movie that kept me on edge almost all the way through it. Thumbs up!