My friend made her own version of this movie which I acted in as the blonde lawyer. Heh, anyway, her version ended happily with a bit of an odd twist.
When I finally watched her "inspiration" for her movie, I was saddened.
The movie catches your interest slowly at first and then holds on to it during the middle and all the way up to the end.
The guy is being threatened with death unless he changes the ending of a story he supposedly copied from the creepy man doing the threatening.
As it turns out, this violent creepy man is a figment of the main character's imagination. The story he is writing is his own, and the ending is that he murders his ex-wife and plants a cornfield where he buried her remains, and then eats the corn in a sort of evil delight.
I was creeped out, definitely. Not for anyone under 13 who is frightened by terror scenes, etc.