Nightbreed tells the story of Aaron Boone, a young man who keeps having nightmares about a place called "Midian." His shrink, Dr. Decker (played by Cronenberg,) informs the young man that he is a murder suspect (a number of families have been brutally butchered.) Boone goes on the run and finds his way to the actual Midian, which is buried under an old cemetery.
Midian is home to a race of monsters, ancient and powerful beings who have banded together to hide from the humans that haunt them. Boone, as it turns out, is one of these monsters, and after he is shot to death he joins them in their underground lair.
All would be going pretty well for him except that his boring human girlfriend tracks him down, and tries to get him to rejoin the human world. Following her is the evil Dr. Decker, who is actually a monster hunter more evil than anything that lives in Midian. This film is based on Barker's novella "Cabal," which I have never read but plan to. It is a very good story, and the intention is that you are supposed to side with the monsters, who are way more interesting than any human character in this film (save for Dr. Decker.) This was the part the studio did not understand and they just butchered the film. In interviews Barker expressed his desire to release a true directors cut, but so far this has not happened. His website gives some good information on how this film should have turned out: http://www.clivebarker.info/nbscene3a.html
As it is, even though the monsters are cool and its a rare chance to see David Cronenberg act, I can't recommend Nightbreed. The film is too disjointed and rather boring. But, as I said, the story is great- there is a really good film lurking around there somewhere. Let's see it!