After suffering unspeakable tragedy at their stately home on the east coast, the three Aperature siblings (proper Isadora, sunny Florence, and somewhat brave Charles Edward) are forced to relocate to the western frontier town of Greenhorn, California to live with their peculiar cowboy uncle. But not all is as it seems in this quiet, dusty neighborhood, as the newest residents soon find out. Children have been going missing in the darkness, while rumors speak of a demonic creature living within it. Uncle Alva may know more than he's letting on; what secrets does he hide behind an off-limits door?