"I'm told that after 2 a.m., I look much prettier if I'm wasted," drawls Katia. "So I get wasted." We're at a bar in the meatpacking district that keeps normal hours but draws its shades after four. A 33-year-old who looks like Sarah Jessica Parker, Katia just moved in with her new boyfriend, Bob, a copywriter at an ad agency. They're intertwined on a couch in the back of the red-walled place.

"We like this bar because the coke isn't as stepped-on as it is in other bars," says Bob, leaning over Katia for a passionate kiss. "But the crowd sucks."

"First thing you should know is, every girl who is out at after-hours is a coke whore," chimes in Katia, resting a hand on her white leather pants. "They're all wrecked."

It's true -- the crowd is middle-aged and, except for a famous writer or two, distinctly unfabulous. "Usually, we go to this place called Chaos -- not the real club, the after-hours place," says Katia. "Last time I was there, the lines out the bathroom were so long! The bouncer came over and yelled, 'The left line is for men and women and the right line is for men and women, too, but if you have any drugs, do them out here 'cause everything's illegal anyway and people got to take a piss.' " They both laugh uproariously and kiss again.

Fifty-odd people are crashed out on couches, chatting animatedly with friends. A dozen more line up for the bathroom as a ponytailed dealer takes Katia to the basement to freebase. "He stuck his tongue down my throat," she complains to a blonde friend, plopping back down on the couch.

"Well, how else do you expect to get it for free?" the blonde harrumphs.

Katia and Bob say they go out four nights a week until dawn -- "as long as you get home in the blue light, you're okay." The only dinner they ever eat is a goat-cheese salad at 5:30 p.m.

"Food slows you down," says Bob. "At least cheese is protein."

Dawn is nearing as a cab stops in a warehouse-heavy section of Williamsburg where gleaming Mack trucks nearly block the narrow streets. On one corner, there's a shingled bar with the iron gates pulled down, but you can hear salsa music blaring and the neon yellow of the Heineken sign lit up from within. Town Cars are disgorging hipsters -- white, black, Japanese, green-haired -- heading back to Williamsburg from a night out in the city but unable to resist stopping for just one more drink.

It's amazing that you can hear the music over the chatter of the vintage-clad twentysomethings scarcely able to raise their pony bottles of Bud to their lips before another thought makes them trip over their words. "I biked here all the way from my friend's loft in Chinatown," says a tall photographer's assistant with a heavy bike chain slung across his chest. "It's such a cool way to see the city -- you feel like Pee-wee in the playhouse."

He buys a gram from a barrel-chested Dominican dealer and gets on a long line to use the "closet" -- what looks like a voting booth, with the same type of heavy curtain. A Dominican guy in a suit comes over and starts yelling: "None of you dancing! You should all be dancing!" He does a little cha-cha. "A couple months ago, I came here and danced until 3 p.m. Now, all these kids here, I don't know what to do."

Two nights later, I go to Chaos, another black door with a peephole, this time in the West Twenties, pointed there by an art director who was first introduced to the place by a black transvestite prostitute. He says he was there one night when the cops shut the place down and everyone ran out the back stairs. The place reopened a week later, though their close call seems to have made them paranoid. When I walk up to the door, no one answers for about five minutes. Suddenly, a voice rings out: "Get the fuck away!" I stand there for a few more minutes until a good-looking white guy with a goatee sticks his head out. Shaking his head, he writes down an address on the back of a Loot matchbook. "Go here, man," he says. "It's not happening here tonight. Just go."

The West Village club he directs me to has the familiar red walls, but it's very clean and well lit, with plush banquettes and white tablecloths. Though it is after dawn, the bar is packed with everyone from drunk Jersey guys to bouncers just off their nightclub shifts to potbellied men in turtlenecks and black blazers. "What do I do?" snorts a short man in a pin-striped suit and pinkie ring. "Why don't you ask me if I water-ski or horseback-ride? That's a better question."

"Cocaine retards the aging process," says a drug dealer with a white comb-back whom we'll call the Rabbi. He's sitting at a round table at the back of the bar -- seated around him are, he claims, a city judge, a cabaret singer who headlines at an upscale hotel, a bouncer at S.O.B.'s, and a top employee of Versace. Surrounded by acolytes, he's in a good mood. "There's a woman in Bulgaria who's been doing these studies, all about how if you do coke you live till 100 and you never get any diseases." He takes a sip of vodka. "My coke is good -- I can afford not to mess with it. I got a beautiful apartment with a running track and swimming pool. I got no problems."