Ever wonder why a door slowly opens or closes while nobody is there? Or why you wake up in the middle of the night for no reason whatsoever? It's because of the Waker.
Every night, it goes from house to house, all over the world, for reasons unknown. You can't stop it from getting into your house, even with the most modern house locks and security, it will always find a way in.
You can never catch it because it only comes when you're asleep. Usually, it just goes into your house and walks around for a while and then leaves maybe taking an old photo of yours so he gets to know you better, and stalk you better, but it has a cycle. Every 4 millionth house it visits worldwide suffers its worst, and every resident of the 4 millionth house goes missing without a trace.
If you are unlucky enough to be in that 4 millionth house, you're screwed. You can try to scream but nothing comes out of your mouth, you can struggle with all your might, but it is too strong. I guess you would find out where he takes you. Or maybe not. Or, you might wake up to find yourself in your own bed, sunlight pouring in through the window...
You won't know unless you find yourself in that 4 millionth house.