On this particular Sunday evening, the mayor is at home. Which is a rarity. The fact is that Tony Williams hadn't really focused on the social aspects of the job until he was actually elected. In the year since then, he says, "I have been to over 940 outside events. People seem to think that the mayor should be at every birthday party and every block party.

"It's not just a physical absence from the home," he adds, "but I think the most difficult impact on our family has been the psychological absence. In other words, if you've been out all day and been beat up all day--say it's been a bad day--I can come home but I won't really be home." He looks at his wife, Diane, sitting next to him on the sofa. "Am I right?"

"That will drive a spouse crazy," he answers himself. "Sometimes she'll want to talk and she'll get these, like, monosyllabic answers, which aren't very helpful . . . You really have to make an extra effort to pay attention to your family, to think of other people besides your own job. So that's been the most difficult transition."

She is nodding the whole time he is speaking, and when he finishes she laughs in agreement. "Well said!"

This is Tony Williams, bow-tie-wearing mayor of Washington, self-described nerd. This is also Tony Williams, bird-watcher and bread baker, stargazer and bookworm. Tony Williams at home.

The first thing you notice about this couple is how normal they are. They live in a perfectly nondescript apartment building across from the Watergate, in a modest one-bedroom apartment with newlywed furnishings. One sofa and one chair in neutral colors, one coffee table, a small area rug, a couple of framed posters on the walls. Some books in the bookcases.

He answers the door in a polo shirt and khakis. She calls out from the bathroom that she has to finish her makeup for the photographer. He brings out a tray of cheese and olives, and chats from the sofa while he waits for her. When she comes in she plunks down next to him, wearing dark gray knit pants and a pullover, and begins to talk as equally at ease as he is.

Diane, 45, appears to be his direct opposite. Gregarious, outgoing, fun-loving, she has no nerd qualifications. They are both very comfortable with who they are. And they are surprisingly open, candid and friendly.

"In a lot of ways," he says, "Diane is a much more social person than I am. I mean, I will do things in public readily, obviously . . . but on the other hand, if there's a room of 100 people, she will move through this room more easily than I will."

She gives him a look.

"Just being honest," he says with a shrug.

"You're getting better," she says.

"This is what I find fascinating," he says. "Small talk requires having a reservoir of useless information for chitchat conversation, and yet I always feel when I walk up to someone they're going to say, 'Leave me alone. I don't want to be bothered.' Or I'll start talking to this person and won't have anything to talk about, which is completely not the case but it's just . . . I don't know what it is."

When Tony and Diane Williams first got together in St. Louis, he says, people were surprised because they seemed so different. They were working in the same office, and Diane invited Tony to her birthday party.

"Just the fact that she had 340 people at her birthday kind of says a lot about her. A lot of people said, 'Oh, he'll never come because he's so wonkish.' "

She says she invited him because "he was a workaholic." She bursts out laughing. "Am I right? You had no social life?"

"When I first met Diane I had no social life. I had a really nice apartment, a coffee maker, and boxes and boxes of books. It was kind of like Gandhi. I had a blanket--really nicely made, though--on the floor, on the carpet and that was my room."

They had their first date shortly thereafter, and commuted for a while after he moved east. But he was ready to settle down and they got married in January 1993. "In some ways I felt unstable, I felt nomadic. My whole life had been moving around the country, always pulling up stakes. Finding someone like Diane who had owned her own home and raised a family [she has a grown daughter who now lives in Washington] was attractive to me. She has a beautiful family."

When they moved to Washington he worked at the Department of Agriculture and she was an auditor at the Corporation for National Service. It wasn't until January 1998, after he had been hired by the District's financial control board, that people began to talk to him about running for mayor.

"I will not run if nominated, I will not serve if elected," he said at the time.

"So much for that," he jokes now. "I thought I would go work in the private sector. I had spent my career working in the government and I thought it would be good to get a different perspective."

It is no secret, either, that she never wanted him to run.

"When you are a public official your life opens up to public scrutiny and I'm a very private person. I didn't want the public scrutiny."

"Well, the other reason was," he says, "that financially speaking, I'm not in as good shape as I would be if I had worked in the private sector. . . . So Diane was saying, 'At least you could work in the private sector for a couple of years and get . . .' "

"And make some money," she says laughing.

". . . And get established," he continues. "I've never really had enough retirement, so it's something I need to think about." He's 48 and still, he says, paying off his college loan from Harvard. "I'm not getting any younger."

"No, you're not," she says, poking him.

He ran, finally, he says, because "I thought I had the ability to really show that government could work in this city and lift the city up to its true promise and potential. And Diane," he says, looking at her with some amazement, "has definitely come on board."

"After he got elected," she says, "it was definitely time to get on board, don't you think? Well, I did campaign some with you."

Diane, he says, did all the financial reporting for the campaign.

"It was beautiful financial reporting," he extols, like a wine connoisseur talking about a rare vintage.

Diane Williams is not at all interested in being First Lady with a capital F.L. She doesn't want his power, she says, doesn't care about the accolades, the fawning, the perks, the car and driver, the security, the special office. It's his job, not hers. She is happy to be his partner and do what she can to help him out, attend important functions.

"I keep thinking my full-time job has aided greatly," says Diane, who is chief financial officer of the Urban League. And not having the office at One Judiciary Square. "Some people were anticipating that I was going to give up my job, but we've always been a two-career family and I wanted that to continue. I've kept my own life. I haven't stepped into the image of Tony. I work every day. I go to the grocery store. I do normal things like normal people."

She has a few favorite projects, including being chair of the Summit Fund of Washington, a private foundation that focuses on cleaning up the Anacostia River and preventing teen pregnancy. She has been honorary chair of the D.C. Coalition for the Homeless, and has worked on the Race for the Cure. And the two of them do what they can do to encourage adoption of children in foster care. "It's good for her to have her own life," he says, "so she's not just sitting there, like, holding a candle as an acolyte.

"From my vast one-year experience," he says, "it seems people understand this. It was always understood that she was going to have an independent, autonomous life and that she would have a measured involvement in this. Her life isn't defined by the public sphere. Right, baby?"

It is getting dark in the apartment, and the mayor gets up to turn the lights on. The view is panoramic, with Memorial Bridge and the Custis-Lee mansion to the left, the Watergate in front, the river and Georgetown University to the right. You can see halfway around the city from their large curtainless picture windows, and everyone in the Watergate has a bird's-eye view of them, too. They seem unperturbed by this.

When the mayor is on city business he travels in a van (a string quartet softly playing on the radio) with one backup car. This is in contrast to Marion Barry, whose large security contingent was always a subject of controversy, and Cora Barry, who used a city car, driver and security men. Diane Williams has no security detail once she leaves the apartment. Neither she nor her husband is interested in the pageantry of the mayor's office and, unlike Barry, Williams rarely "runs hot"--a term used to describe using flashing lights, police escorts and sirens. Williams says that when he took over, he asked the police chief to consult with the Secret Service and follow its advice.

The Williamses begin their day with the mayor getting up at 5:30 or 6 a.m., running 4 1/2 miles or working out at the health club, then coming back to fix his wife coffee and juice in the morning, serving it to her with the paper, in bed.

"I'm like Anthony Hopkins" playing the butler, he says. "Your breakfast, madam."

He'll fix himself some toast and go over his briefing book, and then he's off to work. They talk two or three times a day to discuss the evening's events. Sometimes she goes with him, most times she does not. When he's finished he'll call her and either pick up something to eat on the way home or they'll eat out, more than they would like to. They have eclectic tastes. Their favorite is Coppi's, a northern Italian place on U Street. They also like Galileo, New Heights and Kinkead's. They get deliveries from Luigi's, and he likes to eat lunch at Ben's Chili Bowl or a Somali restaurant, Cafe Nema.

"You just don't feel like cooking," he says. "And it's not so much the cooking. It's the cleaning up." Both of them are good cooks and they really miss cooking a lot.

"I'm an excellent baker," he says, "if I do say so myself. And I'm very good at composition and presentation. The seasoning's not so good. I tend to be bland in the seasoning. She likes seasoning, jazzed up, juicy."

He says this with a wry smile, as though he intends it to be a metaphor for their personalities.

"I'm not bragging," he says, "but I could make any kind of bread. I could make sourdough, rye, which I really had difficulty with, and I got the kneading down. Ryes are hard--different grains, whole grains, can be harder than your regular grain breads. And also getting down to the difference between soft and tasty on the inside and crunchy on the outside, and I was down to the fine points. The only thing I couldn't do is a stupid roll. I had some trouble with that, remember. Your basic dinner rolls."

"Yes, your rolls did turn out horrible, didn't they?" she agrees.

He looks hurt. "Well, they weren't horrible. They just weren't that good."

"They were flat. At one Thanksgiving. Remember? Do you remember?"

He looks annoyed.

"So, no comment," she says, suppressing a smile. "They were tasty."

"We would really like to get a house with a big kitchen," he says, changing the subject. "Because the two things we need in a house are a big kitchen and . . . lots of bookshelves."

They both love to read. One of the most frustrating things for the mayor is that he has so little time to read anything but material from work, newspapers and newsmagazines. He looks longingly at a pile of Sky and Telescope, one of his favorite magazines. He is suspicious of politicians who claim to read books voraciously and still keep up. And after dinner, he is often at the computer until 2 a.m., answering e-mails from constituents.

"That's romantic," he says. "Huh, baby?"

Sometimes on the weekends they will play cards. He didn't know how to play any card games until he met Diane. She taught him how to play solitaire. "I was socially malformed," he says.

They used to like to travel, but they rarely have time for that now. What they both love is bird-watching. "The binoculars are like icing on the cake," he says, "like the xylophone in the orchestra. They're overplayed as having a role. You can tell a lot about the birds by the habitat, the time of year, whether they're flying or sitting. . . . Are they in the water, are they diving, what kind of bill they have, are you in a salt marsh or inland lake? Just forcing you to think about those things is what's fun."

Many people know by now that Tony Williams was adopted at age 3 after having lived with a foster family for three years. His mother, Virginia, recently widowed, raised her family in California and came to Washington after he was elected and has become very active in public life, attending many social and political events, often in place of Tony and Diane. In fact, she is often referred to by constituents as the "Queen Mother." When this is mentioned, the Williamses roll their eyes in mock horror.

"She does go to things all the time," he says. "Any number of public events. Off the record, I'll give you the real story. Off the record, she basically operates like she's the first lady. Off the record, you got it exclusively from us. You deal with it. Please try to be nice to my mom. But basically this is a role. My mother always wanted to be a singer. She always wanted to be a star. My mother, everyone agrees, has a beautiful voice. And she's a real ham, which is fine."

He pauses for a moment, then shrugs. "All that stuff is on the record."

He has become very animated, and Diane gasps and giggles as he continues.

"I really take after my dad. He was a very left-brained type of person--rational, analytical, methodical. My mother, I don't even know if the left side of the brain is even there. It's all artistic, dramatic, emotional and thematic."

It wasn't until he was l5, when his mother took him to a counselor because he was "screwing up in school and messing around," that he found out he was adopted. "My mother said, 'Well, Tony should just admit he was adopted.' And I'm saying to myself, 'Uh, excuse me?' "

"Say, 'Thanks for telling me, Mom,' " says Diane.

"My parents were having difficulties. My dad was not being faithful. They eventually reconciled and stayed together. She did a remarkable job raising all these kids."

He's not sure exactly how many there were. "It's like arguing over the census." They had six kids and adopted Tony, but Virginia raised about three more. "I just kind of ignored my parents, operated under their radar. I was saying to myself, let me out of here because my mother is so dominant. So I moved across country, not to get away, not because she was a bad person, but just to establish my own identity. And then later I realized she is a great person."

Diane Williams doesn't seem to mind that her mother-in-law has assumed some first-lady functions, because it takes a lot of pressure off her.

"She does a lot of things during the day when I'm working," she says.

"She stands in for both of us," Tony says. "Basically they want one of us, some Williams, to be there."

Apart from the mayor's mother, Diane's daughter, Asantewa Foster, 25, lives and works here as well. She made the news this summer when she reported her live-in boyfriend for domestic abuse. He was acquitted of assault last month, but the judge granted a civil protection order requiring him to stay away from Foster for 12 months.

Rather than be embarrassed or ashamed, Diane Williams is proud of her daughter for reporting the incident. "A lot of women are just afraid to come forward," she says. "After it happened, women came up to her and said, 'I've been keeping it in.' My daughter's a very strong-willed person. I really admire that in her, too."

The Williamses thought about having a child of their own, but "decided we didn't want to," he says.

"It's a little late," she says. "And I think it would be almost impossible because the mayor wouldn't be able to spend any quality family time with the children and I think that it's helpful that we don't have any."

One of the lowest points in Tony Williams's first year as mayor was an article in The Washington Post's Outlook section titled "Black Enough?," questioning the mayor's African American credentials. "I got knocked off-kilter. You see, you delude yourself into thinking you can keep all 40 precincts happy. You can't do that and remain true to your own values and principles. And then you've got this notion of, well, am I really black enough, in the back of your head."

"But I was very supportive of you during that time," says Diane. "I told him to just ignore it."

"Right," he says. "Just ignore it. It's crap."

"You can be black and be any kind of person," says Diane.

"As an African American," says the mayor, with an enthusiastic grin, "I would say we want our share of nerds."

"You get these smart kids who don't speak in class . . ." she says.

". . . Because it's not cool," he says, finishing her sentence. "But there's nothing I can do about it," says Williams, who graduated from Yale and went to graduate school at Harvard. "For example, if I were a certain kind of African American politician . . . Well, I just can't connect with the audience in a certain way.

"It's not me. I'm not going to try to be Jesse Jackson. I respect him and consider him a friend, but I'm not Jesse Jackson. I am who I am. There are two deadly things: You can't please everyone and you should never try to be someone you're not."

One thing the mayor has learned that has really surprised him, he says, is that "life in the big city is a fractious and bumptious democracy. They're not sitting around with pompoms, cheering me on. There's a lot of jealousy and envy. I understand that."

As for his wife: "I keep that wall up. I keep myself away from the political happening so I can give my husband the support and unbiased opinions. I don't even think about it."

"You could power this city with methane by all the people saying what they want to do," says the mayor. "But when I took over this city, half the human services were under receivership. The core services were not there. It's not a question of whether you're black, it's whether you're making an impact. I'm proud to be an African American, but the legacy I'd like to leave is not a dramatic or emotional legacy. I would like them to say an African American left Washington the best-run city in America. What's wrong with that?"