A young family moves into a small home and discover something is terribly wrong: Their house is bigger on the inside than it is on the outside. Neither Will Navidson nor his companion Karen Green is prepared to face the consequences of that impossibility, until their two little children wander off and their voices eerily begin to return another story --- of creature darkness, of an ever-growing abyss behind a closet door and of that unholy growl which soon enough will tear through their walls and consume all their dreams.