She looks as cool and polished as a 1940s glamour queen, but Alexandra Ansanelli presents a baffling contradiction. The raven-haired American star of London's Royal Ballet, healthy, uninjured and in the prime of an extraordinary career, is doing what virtually no ballerina in her to-die-for position does -- especially not in a recession. The 28-year-old is about to give it all up. This week Ansanelli dances her last U.S. performance. The former New York City Ballet principal, celebrated for her athletic daring in that company's George Balanchine repertoire, will perform a radically different work here: Frederick Ashton's heated one-act drama, 'A Month in the Country.' She'll pack up her flat and prepare for her last performance ever, next month in Havana, where, with the same Ashton ballet, she will say goodbye to a 13-year career that in many ways you could call enchanted -- or deeply shadowed. Arriving at the Kennedy Center this week, however, Ansanelli delivers only one impression: radiant pulled-togetherness. She is bright-eyed and portrait-ready, her hair slicked in an updo, full makeup, pearl earrings, skirt, pumps and a retro-style black-and-white-striped jacket that could have come from Joan Crawford's closet. 'I love classy women,' she says enthusiastically. She's also tugging along an unglamorous overstuffed duffel bag, crammed full of tights, pointe shoes, stage makeup and various 'bits and bobs,' as she calls them, Britishly, that she needs to get herself stage-ready. It invites speculation about what other baggage she might be carrying -- regrets? Disappointments? Perched on the edge of a sofa, hands clasped in her lap, speaking in an articulate, nonstop stream, Ansanelli gives the impression of utter delight at being grilled before breakfast. She seems exceedingly happy. More than that: peaceful. Over the ups and downs of her professional life, Ansanelli has never offered easy answers. This isn't the first time she has left observers wondering why such a gifted artist who seems to have it all can want to turn her back on it. Her response has a Zen ring to it. 'I feel like my time in the ballet world has reached its max. ... (It) has gotten to a point where I need to move on and live life differently.' She wants to get a driver's license. Play more tennis. And mostly, reunite with the close-knit family she left behind during her three years in London -- a family that has had a singular impact on her art and her outlook. To match her unusual way out of ballet, Ansanelli had an unusual way into ballet. Raised in Long Island's affluent Laurel Hollow (her father is an oncologist), she was an athletic child. At 10, the girl nicknamed Ziti -- for the big dish of baked ziti she'd scarf down after soccer games -- was recruited for a travel team. Try some other things before committing yourself, counseled her mother. Thus the ballet lessons. Then the choice: Giving up soccer was 'a huge thing for me to do,' Ansanelli says. She was nearly 12 when she dived fully into ballet, beginning studies at the School of American Ballet (New York City Ballet's training ground) years later than most girls destined for the stage. Ansanelli wasn't most girls. Success came quickly. At 15, she was a pro, a City Ballet apprentice before she finished her studies. She was on a remarkable streak, all the more so considering she suffered from severe scoliosis, and wore a body cast for six years, putting it on whenever she wasn't dancing, night and day. You could say she was born with her intensity, her driving work ethic -- if so, it came at a cost. Ansanelli, the youngest of four daughters, knows only two of her sisters. One was killed in a car crash as a teen-ager years before Alexandra was born. Twelve years separate Alexandra and the sister closest to her in age. Born late to a family that had suffered unspeakable tragedy, Alexandra was a closely guarded child -- she lived with her parents the whole time she danced in New York -- and she grew into someone who takes nothing for granted. 'We have one life to fulfill everything that we are,' she says, 'and sometimes the door is open for only so long.' She's talking about her decision to leave the ballet world, a decision announced last month, shocking colleagues, critics and audiences. She was getting glowing reviews. (Her recent performance in Balanchine's 'Rubies' was 'as exhilarating as it gets,' raved the Independent.) 'I was sort of astonished in the beginning that she should want to stop,' said Monica Mason, the Royal's director. As a former ballerina, Mason still sounds puzzled by Ansanelli's quitting, saying she is 'courageous' for 'leaving behind this kind of a life, which of course I couldn't imagine doing because I was the opposite. I wanted it to last as long as it could. But that was me.' Why does an artist at the height of her powers walk away? 'It's time,' Ansanelli says, fixing you with her arresting dark eyes. 'I've had feelings about leaving ballet for many years. 'As a complete lifestyle, for me at this point, it's a bit much,' she says. What is much? 'It's being in that world all the time, the ballet world.' Ansanelli says the first glimmers of wanting to leave ballet came a decade ago. She was in a whirlwind then, dancing principal roles within her first month at City Ballet. She worked with Jerome Robbins on 'The Cage' and 'Les Noces.' Choreographers created some 15 works for her, among them Christopher Wheeldon and City Ballet's Ballet-Master-in-Chief Peter Martins. The soccer player's endurance, control and quick feet were the perfect prep for Balanchine's swift, angular modern works. When dancing, she moved like a flame: That long, rubbery body, that fearlessness, that feeling of joy in headlong motion -- the faster the better. Then injury struck, and Ansanelli was sidelined for nearly two years. She had torn the fascia under her heel. But the injury was misdiagnosed for a year and a half as she hobbled to various doctors, who speculated she had cancer, rheumatoid arthritis or other ailments. 'It was a nightmare,' she says. Her foot swelled to triple its size even on anti-inflammatories. She was told she'd never walk again. Ansanelli fought back. 'I wasn't going to stop this way.' She says the time off showed her how easily her dreams could slip away. 'I had the right mix and it worked, and then it was gone. Poof! I was like, `Wow, I'm 18 and I've hit rock bottom.' ' She spent the months dieting (no more ziti), stretching to keep her back limber and finishing her high school degree. Now she can laugh off the drama she faced in her first years as a dancer. 'It's just my karma,' she says, dimples deepening. 'It's nothing else but the way God has created my life to be. I just know when you dip there will be an upswing. There's always something around the corner. It kind of calmed me, actually.' When she finally came back to dancing she was promoted to principal. But she was changed. 'Part of being out of that world opened my eyes a bit, as far as life,' she says. Doubts had taken root. Was this all there was to life? Confined in a rehearsal studio with the same people, day in, day out, dancing a repertoire -- Balanchine and other neoclassical ballets -- that she began to see as limiting? 'What was provided at New York City Ballet at the time wasn't enough for me, as an artist, as a ballerina, as a person.' Ansanelli says she'll miss her London apartment within walking distance of Covent Garden, with nightingales tweeting her awake before dawn. It cost her most of her salary. She'll need an income, but isn't sure where it will come from. 'I hope to work artistically in some way,' she says, but she has no job plans. She's not worried. Still, you can't easily get back to dancing after you've stopped. How does she know she won't regret quitting? 'I don't,' she says, and pauses, seemingly at a loss for words for the only time during the interview. 'The past few months of my dancing have been the best of my career, because I have gotten so much stronger from the classical form. But the real aspect that has enabled me to be so good lately has been my letting go. 'There's no perfect road. There's never a perfect anything,' she said. 'I think it's really what we make of our lives, and we have to make a choice, and maybe it isn't always the best one. But I always go by what I feel.' 