The sassy film actress's move to the stage is just the start;
NICOLE KIDMAN has been so pretty, so cute, such fun, for so long that it's been possible to ignore what was happening. Which, more or less, I'd describe as a great animal growing up. So, for some people at least, it was no surprise that one shoe dropped last week at the Donmar Warehouse as she played five stages of woman in the David Hare-Arthur Schnitzler play The Blue Room, or that many theatre critics wrote fevered reviews of her performance.

But, get ready - the second shoe waits to fall: her performance, promised for next July, in Stanley Kubrick's new film, Eyes Wide Shut, may take us, her and cinema sexuality to new, inner depths. She'll be playing with her husband, Tom Cruise, in that film, but don't be surprised if what you see is enough to make you forget the hype about this "ideal" box-office couple, and wake up to two astonishing actors.

It will be a long way from Days of Thunder (1990), the film on which Kidman met Cruise, and wherein the spirit of honouring every known cliche of the boy's adventure film, she was - at 23 - an expert neuro-surgeon for his driven racing-car driver, trying to keep her hair out of the X- rays. As neurologists come and go, she was an ice-cream strawberry blonde, who looked like 18 trying to be her own older sister, and whose eyes seemed coiled in wonderment, the way her hair gave every sense of wanting to go into spiralling curls last seen on Elsa Lanchester in The Bride of Frankenstein. In those days, with her wide-open Aussie twang, and a dead- on earnest gaze, Kidman was so much the perfect ingenue that no one bothered to ask her to act. Or to realise how far she had come already.

She was born in Hawaii in 1967, because her Australian father, a biochemist then, was studying there. But when she was three, the family went back to Sydney, and Nicole found herself at the North Sydney High School. It happened that a young New Zealand woman was about to make her graduation film at the Australian Film, Television and Radio School. She needed a teenage actress, and she noticed Nicole - who was very close to 5ft 10in already. Kidman did not get that role, but it was a close call, and the woman - her name was Jane Campion - told Kidman to "protect her talent".

What on earth did that mean? she asked herself. She did more plays; she obsessed over Dean and Brando, Ingrid Bergman and Katharine Hepburn; and she was so lofty that she alarmed boys her own age - grown men were another matter. Her parents were as understanding as they could be - her father had become a psychologist who wrote books with titles like Managing Love and Hate. But she was a handful: "I knew I wasn't going to go to college. I wanted to cut loose. I was a nightmare to my parents. I lied to them. There was a time when my mother said: 'I can't live in the same house with her.'"

So she travelled - to Amsterdam, Paris, Italy - living with older men, and coping pretty well. Whenever she got back to Australia she made films, and one of them - Dead Calm, directed by Phillip Noyce, with Sam Neill and Billy Zane - won prizes. And so, at the age of 20, she set out for Hollywood, and almost immediately, while auditioning for Days of Thunder, got noticed by the star and co-writer, Tom Cruise, five years older than she was, and already the star of Risky Business, Top Gun, The Color of Money, Rain Man and Born on the Fourth of July. They got married.

As good as it can get? Maybe. Yet Kidman was now somewhat suspect. There were those who said she was just sweet baggage, trading on her husband's power. No one took Days of Thunder very seriously, and when the couple played together again in the foolish epic Far and Away, she began to get the message about working on her own. Even so, when she made Billy Bathgate - an outright flop - with Dustin Hoffman and Loren Dean, there were stories that Cruise had visited the set when she was doing her love scenes and been just a little intimidating.

There must have been difficult times, as Cruise's career stormed ahead, while she had periods of no work at all. Like many other actresses, she tested for and was turned down on Ghost, Thelma & Louise, The Silence of the Lambs, Sleepless in Seattle, Mary Reilly and The Hudsucker Proxy. But bit by bit she established herself. Harold Becker's Malice was nothing special - just a nice nasty little melodrama - but it gave her the opportunity to move from apparent sweetheart to conniving bitch, and she did it very well. In Batman Forever, as a sexually muddled psychologist, she looked like a beautiful woman instead of just a pretty girl. Indeed, there were a few shots in which she and the lens were like cream filling a glass. All of a sudden, director Joel Schumacher signalled the kind of awe she deserved.

Then, just as she had sometimes lost roles to the likes of Meg Ryan, so Ryan opted not to take on To Die For. Kidman jumped in as the New Hampshire TV weather girl, whose ambition takes murder in its stride. Now she used a sly warping of her prettiness: the girl next door turned into a wide- eyed witch. It was her best and funniest performance yet, and a sign of how much she had been learning.

By this time, Jane Campion had come back into her life with the huge challenge of Henry James's The Portrait of a Lady. It was a commercial disaster. Maybe critics need to try the film again in a few years; maybe its real significance was as a lesson learned. Still, the failure was inescapable: in Campion's previous film, The Piano, Holly Hunter had won an Oscar.

Since then Kidman has appeared opposite George Clooney in The Peacemaker, a very ordinary picture; and she is about to open in America, with Sandra Bullock, as a pair of witchy sisters in the film comedy Practical Magic. No wonder a Hollywood actress jumps at the chance to work with David Hare and Sam Mendes in London - Kevin Spacey showed the same excitement over The Iceman Cometh. But the new version of Schnitzler's La Ronde arose, I suspect, only because Kidman and Cruise had been resident so long in London as Kubrick filmed and re-filmed Eyes Wide Shut.

No one will say anything precise about that film. Kidman's only comment is that it's about "jealousy and sexual obsession". Kubrick took a very long time and a lot of Warner Brothers' money over the film - maybe close to pounds 200m. There were many love or sex scenes in it, and some of them were filmed many times, and then many times again. There's a story that with one great tryst being filmed for yet another time, and as Kidman lifted off her man, so a technician's sympathetic cry wafted down from the darkness above: "Hey, Nicole, I bet you've had more of Tom in this film than in the rest of your life." Or words to that effect.

Cruise and Kidman lived outside London for a while, with their two adopted children. They have much in common: they are both actors who were taken too lightly once because they were so pretty; they are both intense perfectionists who take their work very seriously; yet they are kids who seem able to laugh together. At the same time, there are things that leave one wondering.

Did she adopt his Scientology out of politeness or shared faith? Are they for always and for each other only? Or, are they actors so caught up in their careers and their roles that some parting may be inevitable?

Kidman was asked, by Movieline in 1994, about rumours that Tom was ... "That he's gay? Really? Well, umm, he's not gay to my knowledge. You'll have to ask him that question."

Given that odd take, who wouldn't rather talk to Nicole? About Eyes Wide Shut, say, which will need to be a departure for her to be as good in it as I'm hoping. Truth to tell, Kubrick has seldom mustered much interest in women. But then sometimes an actress can re-arrange a director's way of thinking - that occurred on To Die For. I think Nicole Kidman could be the sexiest animal on screen for the next 10 years - and she might do more stage work, with the Donmar cheers ringing in her ears. She might find herself alone in life. But she's good enough for that.

The Blue Room, Culture, page 6