John Hall is really a drifter who wanders into a little town in Maine. He needs a project and makes the decision to look for employment at the community business: a cloth mill. He is hired to work the"graveyard shift" -- from around midnight to sunrise -- and, along with a couple others, he is charged with cleaning the cellar. The workers strike as simple enough, but while they move underground they encounter an unspeakable monstrosity intent on hammering them .