In his novels and films (not counting the comedies he wrote back in the '60s), William Peter Blatty has dealt with good and evil, but mostly evil, in shocking and memorable ways. In The Ninth Configuration, adapted from his novel Twinkle, Twinkle Killer Kane, he deals with both, but in a way that's more in line with his '60s comedies than his "theological thrillers."

The movie starts out with a pretty cheesy '70s-sounding pop song that feels tacked onto the beginning for no discernable reason, but don't let that sway you. The story takes place in a dreary, atmospheric castle in the Pacific Northwest. It's one of a network of secret study centers set up by the Army near the end of the Vietnam war to determine if the unusually high number of men exhibiting psychoses - many of whom had never done so before - were genuinely mentally ill or just faking it.

Among the inmates in this castle are Captain Billy Cutshaw (Scott Wilson), an astronaut who went loopy on the launchpad - he claimed "going to the moon was naughty, impolite, uncouth, and in any case, bad for his skin." Lieutenant Frankie Reno (Jason Miller) is adapting the plays of Shakespeare for dogs - "Goddammit, somebody's got to do it." Captain Fairbanks (George DiCenzo) thinks he can walk through walls. And that's only three of them. The inmates in this eerie castle, played by a cast of talented character actors in top form, are all bonkers, and if they were all this movie had going for it - which is far from the case - it would still be a very entertaining, laugh-out-loud comedy with more quotable lines than any three good comedies combined (some of which I've scattered underlined throughout this review).

"Listen, I know my rights - I wanna see my urologist."

Into all this lunacy comes Colonel Kane (Stacy Keach), a new commanding officer. Kane speaks in a soft monotone and seems almost somnambulistic in manner. While he has great compassion for the inmates in the castle - "The men may see me whenever they need to." - Kane is dealing with his own personal demons and brings with him an air of mystery.

An interesting relationship develops between Captain Cutshaw and Colonel Kane. Cutshaw believes there could not possibly be a God - or, as he calls it, an "all-knowing Foot" - because if there were, He would not allow all the suffering that exists in the world. But Kane maintains that the existence of God is proven by the good that manages to thrive among that suffering.

"I'm asking Foot to either shit or get off the pot. Diuretic strange gods have been waiting in line."

Trying to describe the plot of The Ninth Configuration would be futile. It's a very difficult movie to discuss unless you're discussing it with someone who's already seen it - but once you see it, you'll want to find someone else who's seen it because you'll want to discuss it. A review in the Santa Monica Evening Outlook claimed, "You have never seen anything quite like it." That was true back in 1980, and it remains true today, almost 23 years later. It cannot be described - you gotta see it. And once seen, it is a movie that inspires great enthusiasm. It makes you want to tell others about it. When you do, you'll find that very few people have heard of it.

"What I don't know for a fact, I don't say, that's the kind of hairpin I am."

The first two acts of The Ninth Configuration are uproariously funny, but a thread of mystery runs through them. The third act deals with that mystery deftly and kicks the viewer in the teeth with an emotional climax that lingers after the movie's long over. It's a hilarious, devastating metaphysical mystery with a touch of cruel horror - that's the best way I can think of to describe it, and I'm afraid it's inadequate. Personally, I think it provides a better argument for the existence of God than a dozen sermons from the pulpit.

Blatty's script, which won a Golden Globe Award, is brilliant, and his direction keeps pace with it all the way. Why hasn't Blatty been directing all his life? This is his first time in the director's chair, but it appears to be the work of a talented veteran. And the cast of seasoned actors do some of the best work of their careers. Stacy Keach is outstanding - I remember him raising his voice only once throughout the movie, but he could not be more riveting if he roared every line. Just as powerful and understated is the late Ed Flanders' heartbreaking performance as Colonel Richard Fell. And bad guys don't get any badder than Steve Sandor and Richard Lynch, who appear in the third act and take part in what has to be, at the very least, one of the top candidates of all time for the best bar brawl ever put on film.

"I think the end of the world just came for that bag of Fritos I had in my pocket."

A few different versions of The Ninth Configuration have been floating around for years, but earlier this year, Warner Bros. released what Blatty says is the definitive cut. The DVD includes a brief interview with and commentary by Blatty, and several outtakes. The version I'd always seen had a slightly different ending - the ending on the 2002 DVD is the one Blatty prefers. To describe it would take far more space than I have here and would spoil the movie for you, of course, so I wouldn't do it, anyway. But this change is slightly mystifying to me because I found the other ending more effective. It does not spoil the movie by any means, though, and you'll be able to decide between the two for yourself because the other ending is included and carefully explained (as are all the other outtakes) on the DVD. As I pointed out earlier, this is a movie you'll want to talk about when it's over, so watch it with someone. The outtakes and their explanations give you even more to discuss.

There is no other movie like The Ninth Configuration. It cannot be neatly filed away in any particular genre and was probably an absolute nightmare for the Warner Bros. marketing team back in 1980. As well as being unique, it is first-rate on every level. Not only does it hold up with multiple viewings, it improves. It is wildly funny, horrifying and deeply spiritual, emotionally shattering and profound, engaging in every way and enormously satisfying.

During his professional life, William Peter Blatty has been a screenwriter, novelist, producer, director, and actor (he has a small role in this movie). As a screenwriter, he wrote what is arguably the best Pink Panther movie in the series (A Shot in the Dark), and as a novelist, he wrote one of the most important novels in the horror genre (The Exorcist). In The Ninth Configuration, he has written, produced, and directed what is simply one of the greatest movies ever made in any genre.

And if you don't agree, then "I want you to drop like an over-ripe mango."