Famed writer Jack Court is a serial killer who possesses a creature that dwells within him and gives him superhuman abilities. On his trail is Sheriff Neil Trajan, certain Court murdered his wife years earlier. When the author is hit by a careless driver, the creature leaves him and ends up with lowly writer, Harold Godwine. Godwine writes faster and better, but is troubled by odd changes. However, Jack survived, and seeks the young author, leaving a trail of destruction, pursued by Trajan.