It is a swelteringly hot August day in New York, the temperature hitting the high 90s, the humidity making even a short walk across town feel like a trek in the tropics. By the time I reach the fashionable Italian restaurant in the newly gentrified Meat Packing district of Manhattan, where I have arranged to meet Rachel Weisz, I am damp and crumpled, grateful from the bottom of my soul to the man who invented air-conditioning.
When Ms Weisz strolls in, though, she looks like she has just wandered off the catwalk. She walks across the room looking immaculately cool in a little black number and heels. Heads turn, waiters dance in attendance, chilled drinks materialise as if by magic.
She has already been the face of Revlon for a while and, as I write, tabloid rumours are flying around that she will replace la Moss as the new Burberry babe. You can see why.
In the flesh she is, there's no other description for it, naturally beautiful in a way that many of Hollywood's new breed of skinny, smiling, over-styled starlets are not. She immediately apologises for being late, though her publicist has already been in touch to put back our lunch date by 15 minutes, a mere blip in the lunar time scale that is celebrity tardiness. Then again, Rachel Weisz is an actress who has never seemed that comfortable with the affections of contemporary celebrity. She once said: 'There's a lot of contemporary actresses I admire, but there's practically no one who's made a colour movie whose career I'd want ... I don't feel very modern at all.'
We do some small talk about New York versus London - she currently divides her time between the two, with a house in Primrose Hill and a loft apartment in Manhattan that she shares with her boyfriend, cutting-edge director Darren Aronofsky. As every profile of her reiterates, she is a Cambridge graduate with a brain to match her beauty. She is a voracious reader, singing the praises of Philip Roth's great American trilogy, and an enthusiast: she will ring me later to rave about a Tobias Wolff short story whose name escapes her while we speak. She somehow seems both eager to please and utterly in control, deftly defining the parameters of the interview without seeming to. She suddenly announces that she is 'starving', but orders the beautiful people's staple: salad and mineral water, albeit preceded by a strong cappuccino. I ask her why she has opted to live in New York rather than Los Angeles, where most film stars choose to live.
'Oh God, no, it was never an option,' she says, grimacing at the very thought. 'I don't do too well there. If you were brought up in London, where you can walk around everywhere and there are theatres, you can't really do LA. I couldn't make a life there. You're in a car all the time, and there are no seasons.'
Spend even a little time in Rachel Weisz's presence and you pick up on two seemingly contradictory things: that she possesses that indefinable sprinkle of otherness that used to be called star quality in the days before meaningless celebrity tarnished the lustre; and that she seems utterly unaware of the same. The beauty that has set the waiters fluttering is undercut with a very English down-to-earthness. 'She doesn't really have any idea of how big a star she is,' says her friend, the Irish actress Susan Lynch, who starred with her in Beautiful Creatures. 'She works incredibly hard and takes the job in hand without any fuss, then she gets on with her life in a very unstarry way. She's just very secure in herself, both on camera and off.'
I am doing lunch with Weisz ostensibly to discuss her new film, The Constant Gardener, which opens the London Film Festival on 19 October, having already been a huge critical and commercial success in the US.
If her star turn in the hammy blockbuster The Mummy, in 1999, upped Weisz's Hollywood profile immeasurably, her role in The Constant Gardener will sustain that momentum while adding to her credibility as a serious actress. It is easily her best role since About a Boy, where she played the babe with the heart of gold who Hugh Grant's character wins when he redeems himself as an all-round good guy. She seemed her most relaxed in that role, perhaps because she was playing a version of herself: a decent, well-balanced English rose.
The Constant Gardener is a whole other ballgame, though. An edgy contemporary political thriller based on John Le Carre's labyrinthine novel, it is directed with customary energy by the formidable young South American auteur Fernando Meirelles, who made his debut with the stunning City of God. Weisz plays Tessa Quayle, the passionate and headstrong wife of Ralph Fiennes's Justin Quayle, a mild-mannered scientist attached to the British High Commission in Nairobi. She is a left-wing idealist in favour of direct action; he is a reserved and dutiful civil servant cocooned in the layers of bureaucracy that attend his station. While he worries over her waywardness, she is on a mission to expose the corrupt pharmaceutical companies using Kenya as a human testing ground for anti-TB drugs. Their roles are reversed following her brutal murder, and the plot merges the political and the personal in a constantly provocative manner.
Le Carre loves the film and says of Weisz: 'She had a difficult role, a girl who has the wealth to afford her principles. But Fernando and her and Ralph sat down and plotted this journey she and Justin take together, where he starts out as almost a father to this wayward girl, then they have this edgy romance, then she dies and becomes almost like his mother, this huge moral guiding force.'
Meirelles plays fast and loose with the story while remaining faithful to the novel's narrative complexity. Le Carre enthuses about Meirelles's 'controlled energy and organised outrage'. Weisz agrees: 'I've never acted in a film where there was so much freedom,' she elaborates, becoming visibly animated as soon as the conversation turns to her craft. 'The way Fernando works is completely unique, insofar as he is prepared to give the actors incredible room to improvise, to bounce off each other, and the script. Usually, you have certain constraints and it's a film actor's job to stay within those constraints; but Fernando and Cesar [Charlone], his cinematographer, just let you go, and they follow. After a while you forget they're there. It's not so much low-budget,' she adds, 'as low bureaucracy.'
Both she and Fiennes thrived on this freeform approach. 'We both really clicked in the scenes where we had to embrace the improvisational atmosphere that Fernando works in,' Fiennes explains over the phone from the Rio de Janeiro Film festival, where he and Meirelles are on a promotional junket for the film. 'Some actors can get nervous when they are given that much freedom, but she thrived on it. It's in her temperament. She's not fearful, she's willing to throw caution to the wind in order to get to the core of a scene.'
The film's great strength is that it refuses to adhere to the good-guy-bad-guy stereotypes of the conventional Hollywood political thriller. Instead, it makes Tessa a rather unsympathetic character in her wilfulness and disdain for convention.
'I loved the fact that she wasn't entirely sympathetic, that she was a lone warrior with all the contradictions that that brings,' says Weisz, over her second coffee. 'She's not Mother Teresa, she's not a saint at all. In fact, she can be quite annoying. Fernando was keen that you didn't go, "Oh, isn't she brilliant, and lovely, and admirable?" It's more believable that she's committed, but she's also a right pain in the ass.'
Weisz brings just the right mixture of passion and self-righteousness to the role, to the point where you can almost imagine her once being this kind of politically engaged animal. 'She has strong opinions,' says Fiennes, 'and I think the role answered something in her. I think she loved playing Tessa for that very reason.'
Weisz's acting career began at Cambridge during her second term, when she formed an experimental theatre company, Talking Tongues, with another budding actress, Sacha Hails, and David Farr, who went on to become director of the Gate Theatre in London. She calls what they did 'fraught naturalism', adding, 'I know that sounds wanky, but it was really liberating and incredibly physical, just me and Sacha and a step-ladder on stage, us hurling ourselves against it, and careering around the stage.'
The play in question was called Slight Possession and it won the Guardian Youth Theatre Award at the Edinburgh Festival in 1987. 'I was hooked,' she says, still animated at the memory of those heady times. 'It just brought out something in me that needed to be expressed, I suppose - that tightrope walk that you need to do to make a play really work.' At Cambridge, she dated the director of Footlights, Ben Miller, much to the chagrin of her many admirers. Apparently, her nickname back then was 'the Trinity Hall heartbreaker'.
Weisz, as her name suggests, is the daughter of Eastern European immigrants - her father, an inventor of medical equipment, hails from Hungary, and her mother, a psychotherapist, comes from Austria. Her Jewishness, she says, is cultural rather than religious, and when the notion of the afterlife is broached, apropos of her forthcoming role in The Fountain, she says, 'Ashes to ashes, that's about where I stand on it all.'
Part of her sex appeal, I would hazard a guess, stems from the fact that she sounds as English as they come, her accent was honed at Benenden and St Paul's public schools, but she looks definably middle European. When I tell her she is regarded as the epitome of 'posh totty', she asks me, perhaps disingenuously, what the term means. This from someone who often appears in lads' mags in various states of artfully arranged sexiness.
I read somewhere that her parents assumed she would pursue a career in law, and were initially sceptical of her acting career. 'They weren't sceptical,' she corrects me, laughing her surprisingly deep and hearty laugh. 'They just thought I was pretty crap. They saw me in my first play and were justifiably underwhelmed.' I ask if there were any actors in her extended family. 'No,' she says, laughing again. 'Not officially, anyway. And I don't mean amateur dramatics. It was more just dramatics.'
Was her childhood intense, then? 'Not at all,' she says, looking slightly alarmed. 'Why would you think that?' Well, what you just said, for one, and the fact your mother was a psychotherapist. It can't, I half-joke, have been easy. She falls silent for a long moment, and it's as if I have crossed an invisible line into territory she is uncomfortable with. It's almost imperceptible, this closing down, but it's there. 'Well, I have nothing to compare my childhood to,' she replies finally, giving absolutely nothing away, 'so I don't know if it was different or not. My childhood was pretty happy, I guess. My parents had a good sense of humour. What they held dear was music and theatre, and I was brought up in a house where those things were cherished.'
Changing tack, I ask her if she has grown accustomed to fame since she crossed over into the mainstream with The Mummy. 'Well, there's a bit of that, but you can steer a course,' she says, suggesting it's no big deal. 'I've never felt uncomfortable with my level of fame. I don't get hassled. Maybe sometimes in a minor way, but New Yorkers are much too cool for that. The thing is, you choose to be an actress, but not to be a celebrity.'
Weisz's route to the top has been circuitous to say the least. At school, she says, 'I wanted to be a detective or a spy. Seriously. I bought manuals and learned to write in code. I'd find a key in the street and it would suddenly be the key to some big mystery. Ludicrous, really,' she laughs. 'But it was just another way of making stuff up, I guess.'
In the school play, aged 10, she had a walk-on part in Alice in Wonderland, as a dodo. 'I never remember reading about a dodo in Alice in Wonderland, come to think of it. It was a non-speaking part, anyway. Utterly inauspicious start.' After the success of Slight Possession, she shone in Coward's Design for Living in 1994, and won a Critic's Choice award for best newcomer. Her subsequent film career has been punctuated by stage appearances, most notably in Neil LaBute's provocative The Shape of Things, where she played the girlfriend from hell, a role she reprised less successfully in the more muddled screen version. Like many English actresses, she seems to need to reground herself in the more visceral and risky business of stage acting from time to time.
Initially, though, it seemed she might become one of the many might-have-beens who appear briefly in Hollywood, then return home to Blighty chastened and lost. There was her brief, but much talked-about, role in Bertolucci's grindingly vacuous Stealing Beauty, in which she bared her breasts for the first and only time. She then starred opposite Des Lynam in the ill-conceived footie film, My Summer With Des, where she met, and to the nation's horror, fell for Neil Men Behaving Badly Morrissey. Their unlikely romance made her, for six months at least, a tabloid staple by proxy, a situation she described as 'definitely not nice'.
She recently confessed to an interviewer, 'My twenties were horrible. It was a very trying and difficult time.' I ask if her thirties have been better: less tortured - she's 34 now. 'Oh God,' she says, 'don't make me come across as a moaner. I think it's unacceptable to moan about anything when you're lucky enough to do what I do. What I'm trying to say is I'm more settled now. The thirties have calmed me down. I know who my real friends are, I know what I want to do. In your twenties, you just do everything. It's just overload all the time. In the thirties, you learn that it's OK to go to bed early if you want.'
These days, Rachel goes to bed early with Darren Aronofsky, with whom she has lived for the past few years. Intriguingly, he is the director of her new film, The Fountain, which has taken six years to realise and is being edited as we speak. 'He cast me right at the 11th hour,' she says immediately, as if to undercut any notions of nepotism.
The Fountain is a characteristically ambitious project from the man who made the mind-bending Pi and the hardcore druggie movie Requiem for a Dream. Weisz plays three characters in three different time frames: 16th-century Spain, the present day, and the distant future. 'I'm Queen Isabella for one third of the film,' she laughs, 'and Hugh Jackman is Tomas, my love interest, a conquistador who's been sent to the Americas. Then we leap to the present, and I'm a woman who's dying before her time of a brain tumour, and then into the future, where death can be deferred. It was almost like making three different films.'
What was it like working with her lover? Did he suddenly turn into Dr Jekyll with a clapperboard as soon as his movie got the green light? She thinks about this for a moment, careful as ever to say something interesting, but not that revealing. 'Well, I got to meet the director, and he got to meet the actress,' she quips, as if she's been saving this one for exactly the right moment. 'It's like you see a whole other side of someone's personality, their professional gifts. I've never seen that kind of tenacity up close before, but that was more when he was trying to get it made. It was such a tight schedule, and he was making a $100m movie for $30m. He wasn't sitting around chatting to me a lot.'
Towards the end of our lunch, I ask her who she really rates as an actress, and she says, without hesitation, Samantha Morton. Her face lights up the way it does when she talks about her work, and she betrays none of the usual faux generosity of her profession. 'It's hard to explain,' she says, 'but she just takes you somewhere else. You can't see the acting. She may not even be acting. It's like she loses consciousness in some way, and just is the character. I find it totally extraordinary and fascinating,' she enthuses, like a genuine fan, 'because there are some actors who are so technically proficient, but you can always see the acting. Not so with her. She's lost to it, lost in it.' She thinks about this some more, then says: 'It's like when you watch Janis Joplin in Woodstock - she's not really in control and it's so intoxicating. That's where I want to get to, to the place where you are not thinking, you're just in it. That's my ambition, really.'
Given that she seems both driven and mellow, professionally ambitious and well-balanced in her personal life, does she have a burning need to act? Could she give it up tomorrow if she had to? Another long, thoughtful pause. 'If you had asked me that in my twenties,' she says, smiling her mysterious smile, 'I would have said, "I can't live without it." Now, I'd say, "I wouldn't want to have to do without it." I really love it. And I suppose I need it.' With that, she gets up to leave for a meeting with a director about another big Hollywood film, every male head in the place turning to follow her departure. That Rachel Weisz, I think, she'll go farther.
· The Constant Gardener is released on 11 November
