"She came on the scene a few years ago and was suddenly there, but she's sort of a mystery," said one acquaintance of the Carters.

"Is she British?" wondered a former Vanity Fair staffer.

"It's like, 'Who is she? Where did she come from? And what is her role exactly?'" said another.

Anna Scott, 42, is indeed British. She is the editor's third wife. The first was a woman he met and divorced in his 20s when he was still in Canada; he separated from Cynthia Williamson, his wife of 18 years, in July of 2000. When Ms. Scott and Mr. Carter began dating in 2003, he was 53, she was 35. Soon after, Ms. Scott became his date to the many meals and parties on his calendar, as well as his friends' vacation homes.

"One night we asked him to dinner, and he said, 'Can I bring Anna Scott?'" recalled Louise Grunwald, the wife of the late Time magazine managing editor Henry Grunwald, who gave Mr. Carter his first job in New York. "I had him for dinner several times when he was single, so I figured that if he asked to bring somebody that it was more important than not."

The couple wed in 2005 at Mr. Carter's Connecticut estate in Roxbury. Ron Perelman, Barry Diller, David Geffen, Martin Scorsese and Robert De Niro were guests, along with close friends like movie producer Mitch Glazer and wife Kelly Lynch, Fran Lebowitz and Ms. Grunwald. "Their wedding was real," Ms. Grunwald said. "I mean, yes, it was big and a lot of Hollywood came, but there was an amazing intimacy to it."

Ms. Carter quickly became the queen to Mr. Carter's kingdom, his partner socially and professionally-helping to oversee the Waverly Inn and later managing the Monkey Bar-and counteracting his occasional shortcomings. Friends say that where Mr. Carter can seem distracted, Ms. Carter is listening intently; where he may come off haughty, she is humble; and when he seems inaccessible, she is quick to make a connection.

"She is young and she's beautiful and she's English and she's poised. That's what she does for his image," said one Upper East Side hostess. "If one tends to be a bit intimidated by Graydon, she is right there with a smile on her face. They walk into a room side by side, and she never stands in front of him or behind him, which in a way is very telling of their relationship. She never gets into trouble."

DURING A RECENT lunch at the Monkey Bar, Ms. Carter described what it was like when she began dating Mr. Carter. "It was completely intimidating, as it always is when you first start dating someone and you meet their friends and you feel under a microscope, and this was a very intimidating, slightly public microscope with these accomplished, brilliant people."

Ms. Carter has a chipper, melodious inflection to her English accent that often sounds like she is reciting a poem to a kindergarten class. She was dressed in a pink cashmere cardigan with only the top button undone and a cream-colored pencil skirt. She had the use of her husband's car that day, which was parked outside: an emerald Mercedes station wagon with a bundle of dry-cleaning hung up inside. 

A look into that microscope Ms. Carter was describing will show her entertaining Larry David at the 2004 Vanity Fair Oscar party; engaging Harvey Weinstein, Kevin Bacon and Si Newhouse in conversation during various cocktail hours; greeting Tom Cruise and Katie Holmes; and, more recently, whispering with Tom and Kathy Freston at the magazine's annual Tribeca Film Festival dinner. Toward the end of many evenings, Ms. Carter would often be perched on Graydon's lap, her arm around his neck, laughing at the joke of whoever was entertaining them.   

"I've often looked across the table and seen Anna sitting next to Sumner Redstone on one side and Warren Beatty on the other," said Alexandra Kotur, Vogue style director, who was once Ms. Carter's intern in the Ralph Lauren PR department. "Who can handle that? But Anna can basically engage anyone in a conversation, and I don't think it's studied."

Perhaps not studied, but learned: Anna Scott's father is a British diplomat who for a time worked as the deputy private secretary to the Queen; her late mother was once the social secretary to the New Zealand ambassador. Born in Washington, D.C., Ms. Carter grew up in Moscow and Yugoslavia, where her father was stationed for work, until she enrolled in boarding school at age 10, the same year her mother died of cancer. "In my father's era, your wife helped you immensely because there is a huge social part of the job and you're entertaining a lot," said Ms. Carter. "So after she passed away, I helped him and kind of took that role for him. It gave me an ability to not be fazed in various social situations."

Ms. Carter graduated from the University of Edinburgh, where she majored in art history, in 1990 and took a job as the assistant in the publicity department at Armani. Two years later, she was head of PR at Ralph Lauren's London office, where she met her first husband, Paddy Byng, whose family owns the Hertfordshire home where the film Gosford Park was shot. They married in '95, right around the same time she met Graydon for the first time, during an advertisers' lunch. They saw each other again a few years later, when she moved to New York and took a job on the international side of the VF PR department.

"I thought she was a charming, beautiful and interesting woman," Mr. Carter said by phone, recalling first impressions. "She had remarkable poise and great inner comfort, which is always attractive."

But both were married at the time. Ms. Carter left the magazine in 2000 to set up a communications department for the Robin Hood foundation and returned to London in 2002 to work with Doctors Without Borders, the same year her divorce was finalized. In 2003, she returned to New York and began dating Mr. Carter.

Ms. Carter declined to discuss their first date, so we talked about the menu instead.

"Are you a 'salad for lunch' person?" she asked. "I try to order different things every time because it's important for me to know what's working and what isn't." She settled on a piece of salmon with sweet peas. 

It was Ms. Carter who hosted a lunch to benefit the Natural Resources Defense Council at Monkey Bar about five years ago, under its previous ownership, and suggested to her husband that the space had potential. (Unlike other "wives of," Ms. Carter doesn't support every charity out there but works exclusively with the NRDC; she is currently talking to Vogue editor Anna Wintour and designer Diane von Furstenberg about making the supply chain of the fashion industry greener.)

"It's hard not to fall in love with Anna Carter," said hotelier Jeff Klein, Mr. Carter's partner in the restaurant, by phone from Los Angeles. He brought up a recent restaurant business transaction that involved a legal conflict. "There were lots of lawyers involved and Anna, this little woman who weighs like 12 pounds and has this chic English accent, says, 'Well, why don't we all get on the phone and work it out?' The genius of her is that none of these big fancy lawyers expected this little woman to ... You know, in the end, she was sort of controlling all of us."

Ms. Carter oversees the daily management of the restaurant and has occasional meetings with Sean McPherson, co-owner of the Waverly Inn, to make sure it is running smoothly as well. "Graydon does the seating every night, but Anna is in the trenches with me hiring managers and figuring out the menu," said Mr. Klein. "Her opinions drive daily decisions like whether we let people who don't know Graydon have a reservation."

Ms. Carter provides support for her husband's work at the magazine as well. "I often use her as a sounding board for story ideas," Mr. Carter told The Observer. "If I am in doubt about a story or a manuscript, I ask her to read it. She's got pretty terrific instincts that I've come to respect and go by over the years."

When asked whether some people have made efforts to get to know Ms. Carter so that she may make an introduction to her husband, she took a deep breath and exhaled. "Sure, there have been people who have thought that I could be a conduit, but my antennae at this point are pretty sharp," she said. "I can usually spot them."

THE RESTAURANTS, THE parties and the celebrities, macro and micro, make up the Carters' public lives. The private is consumed by their daughter, Isabella Rose, who will be 2 in August, and Mr. Carter's four children from his previous marriage: Ash, 25, a graphic designer; Max, 24, who works at Christie's; Spike, 21, enrolled at Pratt; and Bronwyn, 17, who is in boarding school in Connecticut. Cynthia, the children's mother, is, at least physically, the antithesis of Anna: a raven-haired, hippie-ish Elaine Benes look-alike, who now lives in Connecticut.

"I'm very fortunate-it's never easy to be a stepmother to kids of any age, and they've been really great with me," said Ms. Carter.

The couple live in a townhouse on Bank Street in the West Village; on weekends, they try to get away to their home in Connecticut, not far from Ms. von Furstenberg's Cloudwalk farm. "We rented a house in East Hampton for a couple of years and we loved it, but socially, there is too much pressure," said Ms. Carter. "For us, on the weekend, we want to get away and not see anyone. People are very social there and they get offended if you don't come."

"That's the thing," she continued, "I think people imagine us going out every night-and if they can only see! Graydon has two or three things a year that are very major, like Oscars and Tribeca and the after-party at the White House Correspondents Dinner. He needs to do these things for the magazine, and he gets to kill a lot of birds with one stone and see a lot of people in one place. ... It's an important part of his business, and I'm happy to support him, but our real life and friends are separate."

Ms. Carter described how her daughter squeals when Mr. Carter tosses her around in the pool. In the city, Isabella goes to a children's gym in Soho, where she gets tossed into pools of foam. As a result of all this tossing, the child's favorite words are "no" and "again."

When there are no social commitments, the Carters like to hole up at home and watch marathon sessions of TV shows like 24-they watched three seasons during a family vacation in Italy once, staying up until 4 in the morning each night-or HBO's Rome, their current obsession.

"We get in fights because he has much more stamina for staying up late than I do," said Ms. Carter, "So I'll fall asleep and then he's like, 'I'll just fill you in, I'll fill you in!'"

Do they ever discuss what they might do after Mr. Carter retires?

"We totally do and we have a thousand different plans," she replied. "But in the end, he loves his job. I can't see him ever leaving it. This is his life and he loves it, and that's fine with me because I love him."

ialeksander@observer.com