A lewd, gory, twisty-turny murder mystery swirling around Hollywood's porn industry, "Body Double" finds Brian De Palma at the zenith of his cinematic virtuosity. The movie has been carefully calculated to offend almost everyone -- and probably will. But, like Hitchcock, De Palma makes the audience's reaction his real subject; "Body Double" is about the dark longings deep inside us.

Jake Scully (Craig Wasson), an actor on the fringes of the movie biz, comes home from the set of "The Vampire's Kiss" (he's the vampire) to find his girlfriend whooping it up with another man. He can't throw her out -- it's her apartment. But at a casting call, he's befriended by another actor, Sam (Gregg Henry), who offers him the run of his place while he's off doing repertory in Seattle. It's a vast spaceship of a house, complete with rotating bed, large-screen TV and, what's more, a telescope with which Jake can spy on the woman next door, Gloria Revelle (the sultry Deborah Shelton), who fan-dances nightly in her Frederick's-of-Hollywood dishabille.

Enraptured by her unwrapping, Jake tunes in the next night, only to discover that an evil-looking Indian (a refugee from a Western?) is watching as well. The night after, he spots The Nasty again, only this time he's in Gloria's bedroom, hefting a power drill big enough to bore for oil. Jake wants to protect her -- he's already fallen in love -- but shame keeps him from calling the police. "If you hadn't been so busy getting off on your peeping," the scornful detective says later, "Gloria Revelle would still be alive."

But, in a way, she is. In most of his recent movies, De Palma cribs shamelessly from Hitchcock -- here, the models are "Rear Window" (whence "Body Double's" voyeurism), and "Vertigo," in which Jimmy Stewart suffers from a fear of heights (transmuted in "Body Double" to claustrophobia). "Vertigo's" Stewart is gulled by a beautifulimpostor; here, the impostor is a "body double," porn star Holly Body (Melanie Griffith), hired by the murderer to perform the lubricious boogaloo that draws Jake in. After the murder, Jake is watching late-night cable when Holly's dance number from "Holly Does Hollywood" flashes on the screen. That's her. And Jakelights out to unravel the hoax.

De Palma frames this pursuit against the background of the skin-flick subculture, which he replicates with a dead eye -- there's a hilarious satire of a nude cable-TV talk show, which breaks into an even funnier trailer ad for "Holly Does Hollywood." This microcosm becomes a metaphor for the world of "Body Double," which De Palma creates with porn's own tropes and techniques. There is enough skin in "Body Double" to tarpaulin an infield, and more phallic symbols than you could shake a stick at. Women are victims, in the vampire movie-within-a-movie and in real life, and sometimes horrifically so. Unlike Hitchcock, who was languid about suspense but brisk with killing, De Palma brings suspense to the murder itself. Gloria eludes the killer again and again while Jake, downstairs, comes oh-so-close to saving her until the drill, splattering blood, punctures the ceiling above him -- it's an artfully graphic yet oblique montage, with the teasing, frustrating quality of a nightmare.

So much of the plot can be revealed because De Palma has become our most auteurist director, careless with scripts (the dialogue of "Body Double," penned by Robert J. Avrech and De Palma, is typically lackluster), obsessed with images. But there's more at stake here than technique. By stealing the setup from Hitchcock, he's able to discard it, to make us as audaciously indifferent to plot as De Palma himself.

In "Body Double," De Palma joshes Hitchcock's celebrated fear of sex by taking the Master's guilty pleasures and hurling them on the screen in neon-lit tempera Technicolor. For Kim Novak's alluringly distant ice goddess, De Palma substitutes a porn queen, the ultimate sex object, played nicely by Griffith as a gum-popping, daffy bimbo made to stand for all women. Jimmy Stewart's voyeurism in "Rear Window" had sexual undertones, so De Palma makes them unabashedly carnal -- Jake is a Peeping Tom, a connoisseur of late-night porn. Hitchcock's masterpieces are returned to their B-movie roots, particularly by Pino Donaggio's score, which blares uproariously at each suspenseful juncture.

Wasson plays Jake as an exaggerated cartoon of Stewart -- mugging and stammering, he brings out the Don Knotts that was always lurking beneath Stewart's surface. Wasson shares Stewart's innocence, but it's an innocence not of values, but of experience -- he's a naif. When Sam offers him the telescope with a grinning leer, Jake reacts with boyish wonder; and when he plucks Gloria's underwear from the trash and keeps it, he's like a kid with his first bicycle. Jake's not free of sexual feeling, but free of shame about it. It's the villains who try to make him feel ashamed, and when he does (shame keeps him from warning Gloria, or the cops, of her danger), it paralyzes him, with the result, murder.

De Palma's exploration of the outre is meant to outrage. By angering his audience with images that venture beyond the pale, he contends that even the freest spirits among us repress at least some of our basest desires -- we all draw the line somewhere. And pornography, for De Palma, grows out of this sense of taboo -- those who like porn like it precisely because it's forbidden. "Body Double" searches for a life beyond porn and anti-porn. It's a paean to perversity, a kinky, riotous and (who'd have thought it?) thoughtful critique of the pathways of civilized life.