Uma Thurman: Gore, what a scorcher

She has the looks and the talent that have sustained a Hollywood career for two decades. But it has taken a yellow jumpsuit and a samurai sword to bring out the best (and the beast) and turn Tarantino's favourite leading lady from cute to the stuff of cult fiction

Whatever the indulgences of Quentin Tarantino's Kill Bill Vols 1 and 2, these movies have at least found something for Uma Thurman to do. It is hard to believe that an actress of such severe beauty and restless talent could look so lost for so long, but it remains the case that until now it hasn't been entirely clear what Uma Thurman is for, least of all to Thurman herself. In many of her films, she has appeared uncertain as to what to do with her body. And yet as soon as she squeezed herself into that banana-coloured catsuit, sliced the air with a samurai sword and sneered at the camera, she looked purposeful for the first time in almost two decades of screen acting.

Partly this is because her character, Beatrix aka The Bride, isn't really a character at all, but a catalyst for action. But it's also because she needs something to rail against if her presence is not to wilt on the screen. Plainly put, her career to date has been a struggle to live up to the promise of her own lucrative face. And whatever has come along to sharpen the perception of her in the public's collective memory - whether it's the personal triumph of Kill Bill, or her recent divorce from her actor husband Ethan Hawke - has only been for the good. If she didn't turn up in a hit movie or a supermarket tabloid from time to time, no one outside her immediate family would know that she was still in business.

Not that she would care either way - you would be hard pressed to find an actress less addicted to generating gossip-column speculation or tripping along the red carpet. Last week she obliged the press at the premiere party by calling Rebecca Loos a "tramp", before vanishing early, protesting loudly that her current boyfriend was nowhere to be found. She can land a multi-million-dollar deal - like her contract to be the face of Lancôme, which brought her an estimated $5m - but she will then use it to secure more time with her two children. When Lancôme specified a desert location for one advertising campaign, Thurman dug her heels in and refused to stray more than 90 minutes from her New York home.

Despite her endearing performances in films such as Pulp Fiction, Beautiful Girls and Gattaca (the 1997 science fiction thriller on which she met Hawke), it is hard to dispel the impression that Uma is no more than a pretty face. Which is not in itself a bad thing: entire careers have been built on less. But you sense in her a desire to prove that she is more than that. She seems to realise that there is a simplicity to her that cannot fuel a long and idiosyncratic acting career, which may be just as well as her family seems more important than anything. "When I was a teenager, damaged people fascinated me," she has said. "I thought they were the deep ones - and I thought I was more interesting if I saw myself as damaged and difficult. I don't know why. You know, I really wanted to wear glasses. I envied glasses. I envied braces. I envied flaws, all those things that looked like challenges." It would not be cruel to point out that without a decent challenge into which she can sink her teeth, braces or not, Thurman recedes from the screen even as you are watching her.

In the early days of her acting career, it was enough for her simply to be present on screen in order to create the desired effect: wonderment in The Adventures of Baron Munchausen, or pity in Dangerous Liaisons. It seemed so contradictory that those eyes, prone to twinkles of mischief but essentially pleading, were set in a face of Slavic austerity. There was a tension there, and you wanted to know more. Like most young performers carving themselves a niche in a fickle industry, she made good and bad choices. There are films that she made for which "straight-to-video" seems too kind a fate; straight-to-hell might be better for Final Analysis, Batman and Robin or The Avengers. But in among those clunkers were pictures that spoke of risk-taking, innovation and the rebuttal of agents and advisers. She was the hitch-hiker with outsized thumbs in Gus Van Sant's Even Cowgirls Get the Blues, and though the film itself dissolved into incoherence, Thurman's pluck helped her to survive intact. She also brought sparkle to the thankless part of the moll who shuttles between a mob boss (Bill Murray) and an ineffectual cop (Robert De Niro) in Mad Dog and Glory, and you could see her rising to the challenge of playing off her more forceful co-stars.

But more often she seemed not to fit in with the movies she chose - or, for that matter, with movies in general. The hits, like her turn as another moll in Tarantino's pop-culture phenomenon Pulp Fiction, came more by accident than design; the numerous forgettable or ill-advised projects, meanwhile, seemed to sum her up more acutely. She didn't know where she was going, or who she wanted to be.

Thurman was born in 1970 to a father who taught Indo-Tibetan Buddhist studies, and a mother who traded in a modelling career to become a psychotherapist, and grew up in East Coast towns where, she has confessed, she felt like an outsider. "My features were too big and I had these kind of far-apart eyes which looked like I had two fish swimming in my ears. I was severely odd-looking." Then there were her unconventional parents, and her statuesque figure. (James Ivory, who directed her in The Golden Bowl, has called her "the beautiful giraffe".) Like so many of her fellow actors, she found acting to be a convenient and fulfilling outlet for her perceived oddness: in school plays, she could revel in, rather than recoil from, the sensation of being gawped at. You might say she became accustomed to it. At the age of 15, she quit school and flounced off to New York where she found immediate success as a model.

She was being splashed across the glossiest magazines by the time she was launching her film career at the age of 18; shortly after, she began an ill-starred marriage with the British actor Gary Oldman. They were together just shy of two years, and have both maintained a dignified silence on their relationship, with the exception of one comment from Oldman: "You try being married to an angel."

There is in that slyly indiscreet remark a trace of what remains so unsatisfying about Thurman's performances: the conflict on which great acting thrives is nowhere to be found. When we are compelled to watch her, it is because she has struck an ambiguous note or suggested devilry - the sense of fun that she brings to Pulp Fiction is undercut by the suspicion that she may at any moment bare her claws and scratch out John Travolta's eyes. But she hasn't generated enough of that mystery to keep her own image alive. Quentin Tarantino has come to her rescue twice now, and she surely can't depend on him to elevate her career again once the blood spilt in Kill Bill has been mopped up. What will she do without his guiding hand? It might be a hoot for her to work with John Woo in Paycheck, or team up again with Travolta in Be Cool (the forthcoming sequel to Get Shorty). But these are stop-gaps, not star turns, and at this stage she deserves better prospects. If, that is, she even wants them.