This is book 2 of a duology. I read book 1 four years ago, and the Colorado library system never got book 2. I found it now in Alaska, but it is a direct sequel (like, set a day or two after the events of book 1), and I didn't remember enough to fully enjoy it. Also, while there were supernatural elements, it wasn't nearly as creepy as the first. I suspect it would be better reading them back-to-back, but this didn't work on its own.