"Social Disease," an all-out satire of the New York club scene and the creatures who haunt it, isn't whimsy -- it's heavy mettle. Author Paul Rudnick finds most of his laughs when he's at his most nastily outrageous. It's offensive, hilarious, charming and, yes, even alarming. And when the going gets tough (as in a visit to a "straight" sadomasochistic bar), many readers may well flee from the proceedings.

The action begins at the Club de, a Studio 54-ish disco in which Guy Huber (according to Knopf's publicity "the only heterosexual in New York") is attempting to find his new bride, Venice. In the way of his quest is a gaggle of Arabian wives encased in sunglasses and chadors, who are getting into the swing of things: "I am being with the get down," chants Latinda. "The men who are being without the shirts," declares Cardima, "they are giving me the beer, dude!"

Other participants in this roundelay include Caronia, the fashion "editrix" of Glaze (When Caronia was told of man's first steps on the moon, she exclaimed, "Zero gravity! I see scarves!"); foreign film star Ratallia ("Guy liked Ratallia's films well enough, but after seeing more than two of them he felt he had slept with her"); and, most triumphantly, Licky; he's an androgynous Chatty Cathy. ("Darling, being too lesbian for words is a spiritual quality. Now, I adore lesbians, I could squeeze them for hours, but they're well, practical. Earth bound. Hide bound. Alabama bound. Too lesbian for words.")

Rudnick's razor-thin plot -- Venice and Guy's search for the ultimate party (from "East and West, the Villages, West and East, Tribeca, SoHo, NoHo, even that perverse little patch of riverbank Licky had dubbed Teehee"); Guy's kangaroo prosecution for the kidnaping of an Arabian woman; his subsequent imprisonment -- provides the launching pad for plenty of right-on-target satire. But there are missteps along the way, and the ending, I think, is a flat-out mistake.

Certainly, Guy's blueblood parents are already living parodies; satirizing their foibles is redundant. And Rudnick violates his own anarchist scheme and style with a suffocatingly traditional ending.

But most of "Social Disease" is a gloriously randy romp. Rudnick's burlesque of the language brings to mind a peacock preening about in his feathers. (At Guy's trial Licky tells a fat woman judge, "You are beyond faboo, you are fabtastic. Fab-o-rama. Fabulant.") And the campy reflections on modern life are updated Oscar Wilde, or at least sophisticated Fran Lebowitz: "Manhattan waiters are arrogant, but they do eventually arrive, nibbling your French fries. Salesclerks on the other hand refuse to serve at any time. They will deny garments to the wrong people. 'This top wouldn't be happy with someone like you,' they sniff. They don't sell things, they place them."

Rudnick is at his best on his own turf, discussing such issues as hair and the telephone. "Hair shock, Venice knew, the forty-eight hour period following even a minor trim, accounts for fifty percent of all bad hats. A person with a new haircut is naked, disoriented, altogether alone -- am I Garbo or Harpo? Venus or Pluto? Creation . . .or victim?" From the chapter on Ma Bell: "Licky's true heart, which did exist, contrary to popular belief, lay elsewhere. He slipped into one of the bodybuilder's enormous, rank T-shirts and inhaled deeply. He grew centered, anointed, worthy of a deeper emotion. It's time, Licky thought, savoring the suspense, his palms moist. Nestling in the covers, Licky reached for his soulmate, his witch's familiar, the only one who really understood: the telephone."

The satirical richness of "Social Disease" has the snap of a bullwhip. That's why the sappy ending is such a disappointment: It's as if Myra Breckinridge had opted for a nunnery. At its most engaging, Rudnick's world is apocalyptic, anarchistic. These night creatures live orgasmic lives, and when they crawl out of their cabs, they see their own reality: "The sun shone, the planet watusied, all nature was in jubilee" -- fun, fun, fun, until the bomb drops.