As the summer season winds down, Hollywood's weirdest movies start cropping up. And this year is no exception. From David Lynch's "Wild at Heart" to next week's "Pump Up the Volume," strange is the name of the game.

And that applies as well to what is easily the year's zaniest horror film and without question the goofiest sequel — "The Exorcist III." (It is also the season's loudest film — no small feat in itself.)

The first half of this movie plays like a series of vaudeville skits, loaded with dialogue exchanges full of self-conscious quips, like hyper Neil Simon. Then it suddenly shifts to talky horror, saving its big gore scene for the finale.

William Peter Blatty wrote the best-selling novel "The Exorcist," then got an Oscar for the film's screenplay. Directed by William Friedkin, the movie was 1973's No. 1 box-office hit.

Blatty has now written and directed "The Exorcist III," pretending the first sequel didn't exist and wrapping it around an adaptation of his unrelated novel, "Legion."

The main character that connects "The Exorcist III" to the first film is homicide detective Lt. Kinderman, with George C. Scott filling the role originally played by the late Lee J. Cobb.

He is investigating a series of killings in Georgetown that are particularly gruesome (and verbally described in great detail), resembling the motif of the Gemini Killer (Brad Dourif), who was tried and executed some 15 years earlier.

Eventually Kinderman finds that the evil demon from the first movie, exorcised by Father Damien (Jason Miller), has somehow transplanted the Gemini Killer's spirit into Father Damien's body, which is locked up in an asylum.

That's more or less the plot, as Blatty fills the screen with Catholic symbolism, contrived bantering dialogue and eventually tries to sort things out with a rambling monologue from the killer.

Blatty's allowing scenes to run far beyond their dramatic impact is the film's biggest flaw. He's like the salesman who oversells his product until the potential buyer falls asleep.

He also changes all the rules, giving this demon powers his predecessor didn't seem to have the first time around, altering the relationships of characters. And when he plays his final trump card, bringing in a new exorcist (Nicol Williamson), who literally gets stuck to a ceiling and leaves much of his head there when he drops, we can't be sure if he's spoofing or paying homage to Max Von Sydow in the first movie.

There are some big, albeit unintentional, laughs in a dream sequence where Scott visits a heavenly way station. And Blatty trashes "It's a Wonderful Life" in the same way David Lynch's "Wild at Heart" trashes "The Wizard of Oz."

One would be hard-pressed to come up with a movie trilogy where all three entries are as disparate as the three "Exorcist" pictures. The sequels both seem to come completely out of left field.

My favorite line from this one: "I think the dead should shut up until there's something to say."

"The Exorcist III" is rated R for violence, profanity and some fleeting nudity.