Late, late, late. Janet McTeer is about two days late for this interview. She walked out of her house in London to a waiting taxi and the door swung shut behind her, locking keys, ticket and passport on the upstairs landing.

Now the long-legged, broad-shouldered actress is loping purposefully down Ocean Boulevard, dressed for the premiere of her film "Tumbleweeds" in a black, plunge-necked sweater and a bright-hued wrap. She is 6-foot-1. She is ready for a drink.

"[Expletive]," she says of the incident. "[Expletive. Expletive. Expletive.]"

McTeer missed her plane and the next couple of flights after that; instead she has blown in just in time to attend the premiere of this tiny film about a marriage-prone Southern gal who keeps one step ahead of her romantic missteps by running from one man to another with her 12-year-old daughter in tow.

The 38-year-old British stage actress, a sensation on Broadway for her daring interpretation of Nora, the suffocated Scandinavian wife in Ibsen's "A Doll's House" (for which she won a Tony Award in 1997), plays divorcee Mary Jo Walker, a drawling, hormonal, oft-hysterical free spirit with an unbreachable bond to her more rational daughter, Ava (played by Kimberly Brown).

As Mary Jo, McTeer is a woman flailing about in search of her center--and her center always seems to be a man. The Southern accent is laid on with Streepish bravado; the halter dresses, sunglasses and bleached blond hair work as part of a performance that exposes Mary Jo's moral failure and quixotic hope. This week her portrayal won the best actress award of the National Board of Review of Motion Pictures. Already there is Oscar buzz. Already there are comparisons to a similar film now in theaters, "Anywhere but Here," starring Susan Sarandon and Natalie Portman, and--oops--Sarandon the Great is suffering by comparison.

"Is that a parasite?" McTeer asks when the phrase "Oscar buzz" arises. "You must get it in a foreign land . . ." She grimaces and scans the wine list in a restaurant across from the boardwalk, and picks a chardonnay. Next subject, please.

McTeer is entirely unrecognizable from her peroxide turn as Mary Jo. Her hair is short and deep red, styled into elegant curls. She wears a black skirt, low-heeled shoes and no stockings on her solid, chalk-white legs. Her nails are short and unpainted.

The character, she explains, came largely from meeting the real-life person on whom it was based, Joanna Casad, the mother of screenwriter Angela Shelton. Casad, now in her fifties, has been married five times (the last union has stuck for 12 years) and did flee to California with 12-year-old Angela in search of a new start.

"They're huge spirits," McTeer says of Casad and Shelton, her proper accent startling despite the fact that you know she's British. "They take life with a huge bucket of salt and a good margarita. That's why they're not victims. That's very important," she continues. "They have a great sense of life being here to teach you something. They don't like to say, 'This terrible thing happened to me.' They say, 'What can I learn from this?' "

While McTeer appears to have little in common with Casad/Mary Jo--she has never married, has no desire for children, and was voraciously ambitious and independent from an early age--she shares a generational bond with her character.

"Mary Jo's generation--mine included--was brought up by '50s parents," the actress says. "I was brought up to be a wife and mother, even to be a wife and mother with a nice job. But I wasn't brought up to be a career person in my own right, whether I had kids or not. When I was 16, when I hit puberty, I rejected that and got on with doing my own thing. But what you're always doing is some extreme version of your parents' behavior. You're reacting. It's a backlash."

She takes a long gulp of water. "Mary Jo, she appears dysfunctional, even irresponsible. But Mary Jo lives her life. She learns, very much so. And what better thing is there than to be really raw? To be yourself?"

'Not Girly-Girly' Director Gavin O'Connor had an unlikely epiphany while watching "The Charlie Rose Show" one night last year in New York. McTeer was the guest, discussing her Tony for "A Doll's House," and the novice filmmaker was struck by her fearless manner.

"I thought, 'That's Mary Jo,' " he says, taking a break in the theater lobby just ahead of the premiere. O'Connor, 35, used to be married to the 26-year-old screenwriter, Shelton, who wrote "Tumbleweeds" after sketching out her life story for a novel. O'Connor convinced her that it would make a good film (they divorced somewhere in the third draft but remain good friends). He also plays the abusive boyfriend in the film.

"As an artist, you get whispers in your ear about things," he goes on about seeing McTeer. "A light bulb goes on. I've learned to listen to my bones, and my bones were going like that," he says, making his hands quiver.

After seeing the script, the actress couldn't really figure out why O'Connor called her. "I thought, 'This is ridiculous.' I had really, really short black hair. I was wearing a dark, man's shirt [on "Charlie Rose"]. I'm not at all girly-girly." She plunges a finger into some guacamole. "There was no money, no nothing. But I didn't mind. I figured I'd do it: If it comes together, fantastic; if it didn't, I haven't lost anything."

The film's budget--though only $850,000, not much for a film--did finally come together with the help of a few investors, and McTeer threw herself into the role with cyclonic ferocity, having almost no time to prepare for the 24-day shoot in the California desert. She had two sessions with a voice coach. She watched every Sissy Spacek and Tommy Lee Jones movie she could find. She watched "Bastard Out of Carolina" 10 times. She practiced reading the newspaper with a drawl. There was no room to get it wrong.

"It was scary," she admits. "Really, really scary." But she worked at making the accent an organic part of her character. "It's a voice, not an accent," she explains. "It's easier to play a voice because when you really start acting, you lose an accent. A voice is an integral part of the character."

In the end, even Casad couldn't believe that McTeer was British, since from their first telephone conversation the actress spoke Southern. "It took me back. I thought she was Southern," says Casad, whose blond hair is now pixie-short, on her way into the premiere. She took McTeer on a brief tour of North Carolina to give her a feel for the place. "She did a great job. I looked like that at 40, with long blond hair." She pauses a moment. "Janet's just bold. And that's what I was, and still am."

The film convinced audiences at the Sundance Film Festival, where it was first screened earlier this year. During a screening, a cowboy called out, "She looks just like my cousin!" The art-house studio Fine Line bought "Tumbleweeds," and McTeer is being greeted as a major new talent.

Destined for Greatness

Except that there's nothing new about her talent. For more than a decade, McTeer has been one of England's most distinguished stage and television actresses; it's just that Americans had never heard of her.

She grew up as one of two sisters in a village in northern England's Yorkshire district. Her father worked for the railways; her mother was a homemaker. But McTeer always felt out of place, somehow--"like a fish out of water," she describes it. "My mother thinks I was swapped at birth."

She always knew she was destined for greatness. "I was going to be a ballerina, but then I grew. Then I was going to be prime minister. Then a doctor--so I took Latin. I can recite Virgil's 'Aeneid.' I spoke German and Latin. But I still wish I'd learned French."

At 16, McTeer was working in the coffee shop of the local theater and finally discovered her calling, a world where she finally felt she belonged. She began acting, and was accepted to the prestigious Royal Academy of Dramatic Arts, which led her to a career playing most of the classical Shakespearean heroines onstage, and plenty of modern ones, too.

She played Vita Sackville-West in "Portrait of a Marriage" for the BBC in 1990, a production that made it to U.S. television. She won an Olivier Award for her portrayal of Nora in the West End before bringing it to New York.

A career in Hollywood is not something she thinks about. "Never. I still don't. My only criterion is to do work I'd like to watch. If there's a nice script in Hollywood, fine. If there's a nice script on the moon, I'll go there." She considers this. "If I were 22 . . . but I'm 38. I have my own life. If this opens more doors, wonderful. It doesn't mean I have to go through 'em. But I might. And I'm happy about that."

As for her personal life, McTeer calls herself a "serial monogamist." She's crazy about men, she says, just not sure about that old ball and chain, commitment. She keeps apartments in New York and London; her girlfriends have the spare keys.

"I've never wanted to be married. Never wanted to have children," she says, scraping the last smears of guacamole out of the avocado skin with her finger. "But that doesn't mean I can't change my mind. It's a woman's prerogative, eh?"

CAPTION: Janet McTeer transformed her looks and lost her British accent to play the Southern heroine in "Tumbleweeds."

CAPTION: "My mother thinks I was swapped at birth," says actress Janet McTeer.