The Ninth Gate Reviews
Polanski is good with the whole Satanic thing, he seems to know a lot about it. This round operates differently from Rosemary's Baby, more of a detective story whereas Rosemary is an exercise in terror, but the unfolding and understanding of Satanic cult is similar. Orgy, rituals, power seeking, and of course death.
The story is fairly believable, although I have questions about just what happened to the twin bookbinders/dealers.
In some ways I like the ending and in others I think that there could have been a little more to see, but not enough to seriously detract from the movie. Hopefully it leaves the viewer thinking about the story a little. It got me interested in old books and manuscripts enough to do a little reading about occult and strange books from before the 1900's.