Gerry Southern works as the caretaker in the local cemetery. One day, he discovers a grave site has a fresh tunnel bored beside it, and when he peers in, a demon jumps on his shoulder and tries to possess him. The demon has been told by Satan, to return to the living to find another worthy and evil human being to torture after his previous soul went to Heaven due to a wrongful conviction and hanging.  However, Satan advises that if he chooses the wrong soul, that is, one whom he cannot corrupt, then he will be tortured for all eternity. Unfortunately, the first candidate the demon chooses is a man who is pure of heart and does not believe in demons, and therefore the demon tries very hard to convince him firstly that he exists and that he must succumb to the demon or else, and secondly, that he is basically a worthy contender for hell. The demon has until daybreak the next day to steal his soul.