And Wednesday evening, Sotheby's is selling "Hanging Heart," a 3,500-pound, glossy magenta, stainles

There is no artist in whom self-advertisement and self-esteem are more ecstatically united than Koons," wrote former Time magazine critic Robert Hughes. "He has done for narcissism what Michael Milken did for the junk bond."

The pro-Koons camp sees a sophisticated blending of pop art and surrealism. And this side, which includes plenty of heavyweight critics, too, isn't particularly worked up these days because, at least for the time being, this side has won. Long after his mid-'80s anointment as a wonder boy of the New York art scene and a decade after he nearly filed for personal bankruptcy, Koons at 52 stands near the tippity-top of the contemporary art mountain.

The son of an epically fastidious interior decorator, he is shown in the most prestigious galleries, beloved by the richest collectors and coveted by the finest museums. And tonight, he might make history.

Koons's sculptures are the headline attractions this week at auctions at both Christie's and Sotheby's in New York. Christie's sold "Diamond (Blue)," a seven-foot sculpture of polished steel and chromium that fetched $11.8 million on Tuesday night, more than double the artist's previous record at auction. And Wednesday evening, Sotheby's is selling "Hanging Heart," a 3,500-pound, glossy magenta, stainless-steel Valentine's Day heart that hangs from what looks like curly gold wrapping ribbon and took 12 years to make. It's expected to sell for $15 million to $20 million. If it goes for more than $19.3 million, it will surpass a record set in June by England's Damien Hirst and become the most expensive work by a living artist ever purchased at auction.

All this attention, of course, will reignite the debate about the merits of Koons's work. Which leads back to Koons himself, because as much as any artist today, his intentions seem a crucial part of deciphering his canon -- vacuum cleaners encased in Plexiglas, a 43-foot puppy covered in flowers, tacky-looking wood carvings of cherubs and pigs, and on and on. Is he lampooning commercial culture or admiring it? Is he a calculating showman or an idiot savant? Is he laughing with us or at us?

The answers seem to matter. If "Hanging Heart" is the work of a cynic, it comes across as one thing. If it is the work of a naif, it comes across as something else. This is why we want to know what Jeff Koons is thinking.

So we're just going to ask the guy.

The New Factory

Koons's studio takes up the entirety of a huge one-story windowless building on a corner in Chelsea. There is a buzzer by the door with a single, unmarked button on the intercom. The only sign that you've come to the right place are the words "private studio," in small type, on a nearby wall.

The ascetic entrance belies the hive of activity inside. Eighty-eight people work here, most of them art-school graduates in their 20s and 30s. They are divided into cavernous white rooms and huddled around works in progress, or they are typing on large-screen computers. It's quiet except for the mechanical hum of printers. The atmosphere is somewhere between dot-com start-up and laboratory.

There are half a dozen hyper-realist paintings, some of them hanging on the wall, others lying flat on tables, each being dabbed at by an artist or two. The Hulk is a subject, as are naked women, Play-Doh and lobsters. There is an entire room devoted to what look like swimming-pool flotation devices with caterpillar heads; you need to tap them with a knuckle to believe they are made of metal, not plastic.

The Willy Wonka behind this factory is dressed today in faded black jeans and a blue button-down shirt. Koons is youthful and handsome in a way that seems strikingly conventional, as though he ordered his face from a catalogue. His handshake is soft and he speaks in the becalmed tones of a yoga instructor. The introductions are over in a blink.

"I don't know how much time you have," he says, trailed by an assistant carrying ring binders with photos of projects in various states of completion. The work and how it is made is what he's comfortable discussing, and there is a lot of work to discuss. He stands by a table covered with identical-looking balloon-sculpture swans, which aren't made of balloons at all, but silicone rubber. These are mock-ups for an 11-foot-tall piece, which is being fabricated in Germany through a process that sounds astoundingly arduous.

"What I love about the swan is the harmony," Koons says, picking one up. "In art, the first form of segregation is really the viewer's sexuality, whether they're male or female. So to really have an objective vocabulary is to have the work communicate no matter what one's own sex is. So here's this beautiful harmony where you have feminine interior but the front is quite masculine."

This, it turns out, is a fairly typical Koons riff. For all the apparent levity and wryness in his productions, Koons the man exhibits neither quality. He is sunny and earnest, or maybe he is feigning sunniness and earnestness in a manner that is thoroughly convincing. Talk to him long enough and either seems possible, yet both are hard to fathom. How could a guy who radiates almost childlike innocence make paintings and sculptures of himself in the naked embrace of his now ex-wife, an Italian X-rated film star named Cicciolina, as Koons did for a series called "Made in Heaven"? And if the innocence is a put-on, how could he possibly keep up the act for so many years?

"This is what is fascinating about Jeff," says Donald Young, a gallery owner in Chicago who exhibited Koons in the '80s. "He's a persona, he projects a persona. I wouldn't pretend to have ever gotten into his inner psyche. I'm not sure who has. But the longer he lives that persona, the more he seems to become it."

For every acquaintance who swears that the public Koons is a kind of facade, there are two who think that it is not.

"He's completely sincere," says art historian Robert Pincus-Witten, who has known Koons for years. "It's hard to understand because of the daring range of subjects he's taken on, but it's not an act. I've been with him when a child has walked into a room and asks a question and he can lose himself with that child for half an hour. He's very astute and he works with exceptionally powerful people in the art world, but there is a guilelessness about him that is very real."

Koons walks to a different room and approaches a scale model of an industrial crane, which dangles a black steam-engine locomotive, which is pointed straight down, hovering above the ground. It's a prototype for a project commissioned by the Los Angeles County Museum of Art. When completed -- a few years from now, at minimum -- it will stand 161 feet tall.

"It's a 1943 Baldwin steam engine," says Koons, reaching under the table and flipping a switch on. "We're building it from scratch. We have the blueprints and we've scanned them in, and it will be absolutely authentic realism. If this person," and here he points to a tiny model man, who is part of a crowd standing under the locomotive, "were a conductor who was on a 1943 Baldwin his whole life, he would say, how did they do that?"

The model chugs slowly to life. You hear gears change, valves pump and the wheels start to spin. A "performance" like this will happen three times a day, when the museum opens, at noon and when the museum closes. Steam is now puffing out of the top. The whistle blows.

"It's on a bell curve," Koons shouts over the din, "so every moment, it's going faster and faster. It will come to a plateau at about 80 miles an hour. We could go to 100, but at 80 it's just a blur."

"Train," as the project is known, has all the hallmarks of Koons's style. It's immediately gettable (look at the choo-choo!) and on some level utterly confounding. (Who on Earth would spend years creating this?) It also requires a meticulousness that verges on insanity. That has been part of Koons's brand since he showed up on the New York art scene in 1985 with basketballs floating in tanks, and it isn't a charade.

His perfectionism suffuses the studio. In one corner, three assistants are unpacking red chain links that have taken years, and several different manufacturers, to fabricate to the specifications in Koons's mind. Having already sold art that uses the old -- and, to his mind, inferior -- chain, Koons will get in touch with the owners of those pieces and swap in the new chain, although it's safe to assume that only Koons will be able to tell the difference.

His paintings are created with an elaborate, color-by-number system that allows him to control every one of the thousands of shades that his assistants apply to a canvas, and map out exactly where those shades should go. All room for interpretation is eliminated.

"Three people have been working on this for nine months," Koons says, gesturing to a canvas with a lifelike rendering of a Playboy model named Heather Kozar, whose midriff is covered by a giant lobster. "There's another four months to go. We have to make the hair look individual."

Though he oversees a kind of high-end assembly line, it's hard to imagine anyone familiar with his work habits alleging he is in it for the money. Because nobody in it for the money would run a business the way Koons does. For the design and manufacture of the "Celebration" series, which he began in 1994, Koons didn't just drain his own bank account to the point where he briefly had to close the studio and couldn't afford a ride on the subway. He also spent millions lent by a consortium of galleries that were his financial backers. And when that spigot closed, he sold pieces that hadn't yet been made, to collectors willing to keep him afloat.

"He's quite willing to ruin himself and ruin the gallery to get it right," says Antonio Homem of Sonnabend Gallery in Manhattan, which was part of the consortium. "Which I think is a totally romantic notion and why I think it's funny when I hear people accuse Jeff of cynicism. You have to realize what his work costs in terms of time, money and devotion, and then you have to wonder -- could anyone spend so much time, energy and devotion in cynicism?"

In the Background

Koons is married to a woman named Justine Wheeler and the couple have three young boys, with a fourth child on the way. He lives in a townhouse on the Upper East Side. If you have the impression that he disappeared for a while, it's because he was sidetracked for much of the '90s by a child custody battle with his first wife, Ilona Staller, a.k.a. Cicciolina. The marriage lasted just a year, but the custody battle over their son, Ludwig, now 15, would last more than a decade and cost Koons a fortune in legal fees -- another reason he nearly went broke. The child was abducted by Staller in 1994, Koons says, though five years later, Staller prevailed in a ruling by Italy's Supreme Court. Ludwig has grown up in Rome.

"I might get to speak to him for a minute on a birthday," Koons says. "Then I can't get through for another year."

"Hanging Heart" is a love offering of sorts for Ludwig, who Koons hopes will eventually seek him out. If he does, he'll be the second child of Koons's to reconnect in adulthood. He had a daughter with a girlfriend he dated while attending the Maryland Institute College of Art, and though Koons says he wanted to get married and raise the baby, she was put up for adoption. Part of Koons's drive to become famous, he has said, was to raise his profile so the child could find him, which she did. She's now 32, lives in New York and is close to her father.

Surely Koons had other motivations for becoming famous, but he seems unwilling or unable to describe what they were. Like most questions that attempt to hurdle the moat of his beatific gaze, the subject of personal ambition is deflected with answers that sound like an art-school sophomore's idea of diplomacy.

"After I got out of college, I realized how committed I was to art," he says. "And I realized how much I wanted to participate. I always wanted to have my work interacting with Rauschenberg, Lichtenstein, Dali, because I really wanted to be part of that vocabulary. I really wanted to learn that vocabulary."

Koons began sketching as a boy in York, Pa., doing pencil portraits for family and friends. His parents hired an art teacher to give him private lessons, which he dropped when he reached junior high, his mother recalls, because art lessons at that point weren't cool.

"He picked it back up when he got to 11th grade," says Gloria Koons, who now lives in Florida. "I can tell you for sure that he got all the talent from his father, not me."

Any attempt at a psychobiography of Koons must start with the now-deceased Henry Koons, a former military policeman who spent decades running his own very successful interior-decorating business. His store, a showroom of fabrics, furniture and paint books, sounds uncannily like the template for his son's studio. The elder Koons employed a handful of seamstresses to craft draperies exactingly designed by the boss.

Henry knew what he wanted in all things aesthetic -- especially, it seems, when it came to the family Christmas tree. The Koonses threw a well-attended Yuletide party every year, and Henry considered an impeccably decorated tree a chance to wow potential clients. It always stood about 25 feet high, in the foyer, rising past the wrap-around staircase to the second floor. He festooned it with matching glossy balls, which he -- and only he -- would painstakingly arrange for days.

"We called it 'that stupid tree,' because we weren't allowed to touch it," says Karen Koons, Jeff's older sister, who lives in Wisconsin and works for a company that manufactures polymers. "We had our own little tree, but the big one was Dad's. It was his perfect object, his work of art."

Henry and Gloria supported their son's decision to become a full-time artist after Koons quit a commodities-trading job on Wall Street because he could think of nothing except the conceptual sculpture he was fabricating in his spare time. In 1985 he was focused on "Equilibrium," the series of basketballs floating in aquariums, but his cannonball into the international art pool came in 1988, with a show called "Banality." It opened in three galleries at once and featured, among other items, wood carvings of smiling bears that Koons commissioned from European craftsman, as well as a porcelain of a sexy blonde hugging a slightly alarmed Pink Panther.

Sides were chosen up and speculation began about the inner life of the cheerful cipher behind this now voluminous body of work. Ardent fans such as Michael Govan, the director of the Los Angeles County Museum of Art, think Koons creates ambiguity about himself, in part, because it adds a layer of ambiguity to the work.

"Jeff plays it a little bit," Govan says. "He knows what to say to not give it away, as if there is something to give away."

You get the sense that Koons has carefully studied Warhol and Dali and other art impresarios and understands how biography can enhance work, and vice versa. Ultimately, he seems like a high-functioning obsessive-compulsive with a deft sense of the art of public relations and deeply original intuitions about the power of the object. He lives in the place where naked commerce meets hopeless sincerity, and everything seems to flow through him: Disney, Venice, porn -- even Led Zeppelin, which turns up, barely visible, in the background of a painting getting final touches in his studio.

Just don't expect to be edified when he explains why.