Charlize Theron: Falling angel

Charlize Theron will be at the Edinburgh Festival on Thursday, answering questions on stage - if you are anywhere in the vicinity, you should be there, for Theron, at five feet and nine-and-a-half inches, is one of the spectacles of the world. If there's a question time - and she's as much of a sport as usual - I dare you to ask the question, "Charlize, how much longer is all this going to continue?" I know, she still seems like a newcomer. But she knows how easily the new face turns unduly familiar.

She gained a foothold in our fickle minds in 1997-8. That's when she played Keanu Reeves' wife - a hot Southern girl - in The Devil's Advocate, and when she was the stunning supermodel in Woody Allen's Celebrity. Indeed, she was the honey-pot in that film, tall, blonde, about 23, cool, lustrous and probably already paranoid about the girls who were 21 and might be taller, leaner and just a little bit more than a 36B.

It emerged that she had a real story to tell. Far from being from the South, or one of the beach communities in southern California, Charlize Theron turned out to have an astonishing life. She was born in Benoni, South Africa and grew up on a farm, the daughter of a German woman and a Frenchman. She spoke Afrikaans as her first language and English as the second. But when she was 15, her father attacked her mother with such intent of doing her harm that her mother shot and killed him. No charges were ever preferred, but this is the kind of real-life experience that seldom attends our movie greats.

Maybe because of that, and maybe because she saw talent, the mother got the daughter off the farm as quickly as possible. At the age of 16, Charlize began a modelling career which rapidly took her to New York. When modelling turned sour, she tried to be a ballet dancer. But a knee injury put and end to that, so her mother packed her off to Los Angeles to see what she could do about the movies. That was only a few years before The Devil's Advocate, Celebrity and a spread in Playboy in May 1999.

So there she was, in 1999-2000, with a foothold. Woody Allen had gulped when he saw her and he had given her his on-camera treatment, ogling her great body and her rather lazy-looking eyes. But do you have any idea of how many thousands of young women, virtually as beautiful, and variously as lazy or as energetic, there were in Hollywood then, or are now, ready to cut a rival's throat? It may be all very well to look lazy, but don't risk trying it if - for the sake of argument - you are in a pool of talent that includes Nicole Kidman, Julia Roberts, Reese Witherspoon, Natalie Portman, Scarlett Johansson, Kate Beckinsale, Cameron Diaz, Anne Hathaway... If a good part for a woman under 35 comes along, more or less all of those women are going to know about it, and plenty of them are ahead of you in the pecking order. And if, for a moment, you really get to the top of your class - if you feel like Nicole Kidman or Julia Roberts - be aware that those superstars are all too conscious of every Charlize Theron that comes along. In the same way, Charlize will have informed herself about the girls who are even a couple of years younger than she is and may be putting polite voodoo needles in their dolls.

For a few years Charlize Theron did movies that proved she was in the business, but not much else - Mighty Joe Young, The Astronaut's Wife, The Cider House Rules, Reindeer Games, The Yards, Men of Honour, The Legend of Bagger Vance, Sweet November, 15 Minutes, The Curse of the Jade Scorpion, Trapped, Waking Up in Reno, The Italian Job. Take the last one - she was the girl in the gang, and she had a couple of nice scenes, but she wasn't as cute as the cars in the end. And anyone could have played the part, and all the other parts she played. What that means, sooner or later, is that anyone - or someone other than Charlize - will be playing them. You're making a little money and collecting some celebrity boyfriends so that the business won't feel too bad about you when you're gone.

Whereupon, something stirred, something that had survived out in the midday sun of Africa, not to mention the horrible family tragedy, and Charlize said she would play Aileen Wuornos in Monster.

She put on weight. She let her teeth and her nails go "poor". Her hair was ratty and her let complexion deteriorate, as if from a life of fast food. She was playing a mess, a girl who sold herself for sex and then killed some of the men when they treated her like trash. She was not recognisable, and that is too easily interpreted as "she was acting at last". But she was acting, and she became this shambling, undecided hulk of a creature; effectively, she said to the audience, you don't have to like me, but just watch how much I know about life. (In fact, she was more than acting in Monster - she was one of its producers.)

It would be simplistic to say she won the Best Actress Oscar in 2004 because of the sacrifice she had made with her own looks - though there is a connection between awards and the willing denial of beauty. It is taken very seriously in a community that still warns you to come back from rehab as cute as ever. Charlize honoured that pact. By the time she accepted her Oscar, she looked as good as ever. Whereas, if she had come onto the stage of the Kodak Theatre while looking remotely like Aileen Wuornos, she might not have taken the statuette home.

People said her world would change. Now, she would be taken seriously. Now she was ready for a great run of homely, overweight women of about 30 who have movies made of their lives. I'm kidding - we don't do films like that. Charlize hurried back into shape. She was Britt Ekland (and very good, too) in The Life and Death of Peter Sellers. She did Head in the Clouds (which I challenge you to remember), and she found an intriguing role - playing a striking worker in North Country, a film about the working class, labour disputes and women with ideals. She was nominated this year for another Oscar but no one went to see the film.

She then did the awful Aeon Flux. She appeared on television as "Rita" in a few episodes of Arrested Development. And there's going to be a film called The Brazilian Job in which she plays the girl from The Italian Job. In other words, Theron has done nothing done since Monster to help her in mapping out a future. The world has not learned how to want Charlize Theron looking like hell. It likes her gorgeous, and yet it can see that Scarlett Johansson is younger (and always will be).

Somehow or other, Theron has to do something similar to Nicole Kidman's achievement after the latter's marriage to Tom Cruise ended. She has to seize parts that say, I chose these, I found them, I told them I could do it, and look, it works. What that means is that she has to go find the parts, know how to secure them and make her will felt strongly enough that they turn out unusual and good films. That so many actresses do ordinary work is testament to how tough that challenge is. Most of them do what they can get and spin it out until 40, if they're lucky.

Spare a thought for Charlize Theron, and actresses like her, as she makes a splash in Edinburgh this week. She's looking for something wonderful or monstrous - not much else is going to be in the running. And, like the sudden violence and horror she experienced when she was a kid, she is betting that some magic will come into her life.

Charlize Theron will be interviewed at the Edinburgh International Film Festival at 6pm on Thursday. For more information: www.edfilmfest.org.uk, 0131 623 8030