Doreen is about to marry the man of her dreams, Hank, a mild-mannered guy who is equally as excited about marrying Doreen. However, Doreen's older brother, a wild man named Travis who's been estranged from her for several years, shows up to make amends, but instead he accidentally curses her. Doreen is now possessed by the devil. In Las Vegas is a homeless man known as Johnny Priest, who is the last known person to perform an exorcism in America. It's up to Travis and Hank to put aside their differences and travel from Chicago to Las Vegas to get Doreen an exorcism before it's too late and her soul is lost forever.