Final Cut finds James, a screenwriting student, in a compromising position after a rival student, Adler, steals his screenplay. Unable to prove that Adler plagiarized his script, James and his crew are forced to start from scratch to create an entirely new film in a very short amount of time. Rachel, the film's director and James' longtime girlfriend, suggests that they make a horror film, which prompts James to quickly get to work, researching genre films and the psyche of serial killers. Production gets off to a good start, and things seem to be going swimmingly for the cast and crew. Unfortunately, before the crew can wrap, an actual masked murderer shows up on set... one who is hellbent on bringing their slasher film to life.

Abandoned, abused by the police and in the throes of withdrawal, Nadine, a drug addicted young prostitute, returns to her childhood home and the mother she ran away from. Nadine's mother, Delilah; a fanatical Christian who believes demons have possessed her daughter, searches for a "cure" for Nadine's erratic behavior. When she finds a rogue preacher willing to exorcise her daughter for a fee, neither realizes they have invited the devil into their home. While her mother turns a blind eye to the bizarre practices unfolding in her own home, Nadine, racked with mental and physical pain, has no choice but to put up with the preacher's increasingly violent charade.