Churchill called them his 'Golden geese' - the dedicated young men and women who laboured around the clock to crack Hitler's codes during the Second World War. For more than half a century, their heroic work remained a secret that many of them took to their graves.

Now their extraordinary experiences have been turned into a major film which brings to life the previously shrouded world of the codebreakers of Bletchley Park. For most of us, Enigma, starring Dougray Scott, Kate Winslet and Saffron Burrows, will afford a rare glimpse into the past. For 80-year-old Marie Bennett, however, the film will see her private memories revealed for the first time.

Like Winslet's character, Hester Wallace, Marie worked in Bletchley's Hut 6, where the Enigma codes were broken and she helped decipher the enemy's deadly messages. Her efforts helped to shorten the war and saved the lives of thousands of Allied servicemen.

The all-British, Pounds 3 million film, produced by Mick Jagger and with a screenplay by Tom Stoppard, is based on the best-selling book of the same name by Richard Harris. It tells the story of Tom Jericho, a Cambridge student who is recruited to Bletchley for his mathematical skills. There, he becomes infatuated with the mysterious Claire (Saffron Burrows), but as her loyalty is cast in doubt, he falls for the more homely charms of code clerk Hester, played by Kate Winslet.

Harris spent weeks at Bletchley researching the stories of Marie and those like her to create the character of Hester. The resulting screenplay, says Marie, is an accurate portrayal of her life then. 'I' ve seen some of the film and it looks very realistic,' she says.

'It's odd seeing my experiences on film because it was such a unique time, and secrecy was so ingrained in me that for so many years I never talked about what I did, not even to my husband. Now everyone can finally see what we achieved. It's very emotional.' In 1939, Marie was an 18-year-old accounts clerk from North London who had volunteered to join the ATS, the women's branch of the Territorial Army. Her work in the ATS was unremarkable until, at the end of 1941, she was mysteriously ordered to go for an interview at a government office in Piccadilly.

She recalls: 'I had no idea what it was about.

But I recognised that the officers who were interviewing me all wore Intelligence Corps badges, so I realised something was afoot.' Two weeks later, and with no idea of what her mission was, she was sent to Leicester.

'We signed the Official Secrets Act and were set to work in a huge mansion filing huge card indexes inscribed with incomprehensible groups of letters,' says Marie. 'It all seemed very strange.

Later, I realised we were building up a reference book of the German call signs, which was vital to help interpreting the nature of the messages.' On May 4, 1942, she was sent to Bletchley Park in Buckinghamshire. Like Hester, Marie was assigned to Hut 6, where much of the codebreaking took place. 'It looked so ordinary it's hard to imagine such important work was going on,' she says.

In fact, behind this anonymous facade were assembled some of the finest brains in Britain, dedicated to cracking the encrypted messages passing between Hitler and his forces.

The Nazis believed many of the codes were unbreakable, but with the help of electromechanical machines called bombes, the teams at Bletchley unravelled much of the chilling dialogue, and revealed vital information about enemy movements.

Marie was unaware of most of this.

Working day and night in a cold, damp hut lit by a single bulb, she pored over thousands of German morse code messages picked up by listening stations all over the country. The messages were incomprehensible to the untrained eye.

But for Marie, schooled in frequencies and code, they were manuscripts waiting to be interpreted.

'We were looking for clues and patterns,' she says. 'A lot of the time we were looking for mistakes. Each German station was supposed to change its call sign at midnight. If they forgot, we could help break the code for the day.' Of what took place around her, Marie knew little. 'No one did. No one talked to each other about their work.

You could be risking someone's life.' Indiscretion was not tolerated.

Marie recalls an officer talking about her work in a pub. She was never seen again.

But the young workers still made the best of their time. 'We were dedicated, yes, but we were young and we did what young people
do,' Marie recalls with a c h u c k l e .

'There was a hectic social life. There were drama clubs, cricket clubs and, of course, we had regular dances. On days off, we took off to London, hitching a lift with lorries and booking into bed-and-breakfasts. We didn't get any sleep, but who needed sleep?' As in the film, there were plenty of dalliances. 'I had a few romances, although nothing serious,' says Marie.

'We were no different from young people now... and there was a sense of urgency about everything. To me, it felt like it wasn't real time, as if time was suspended until the war ended.' There was, however, little privacy.

The codebreakers were billeted with local families or assigned unfurnished rooms in deserted mansions.

Marie was on leave when the war ended. When she returned to Bletchley Park two days later, her operation had ended. 'Already people were destroying all evidence of everything that had taken place. It was a strange atmosphere, but there was a sense of 'We've done it! We've won the war.'

That's what it was all about, after all.' She left the Army, became a teacher and had two children. For years, she told no one about her war work.

But she kept in touch with many of those whose lives were bound together by their time at Bletchley. Each year, dozens of them hold a reunion. ' Sometimes people I haven't seen for 50 years turn up but I always recognise them. I think we worked so closely together that their voices and mannerisms are absolutely familiar,' she says.

'When we get together, it feels like we're 20 years old all over again.'

Many of them helped campaign to save Bletchley for the nation when it was due to be demolished. Nine years ago, it was turned into a museum: Marie's uniform is one of the exhibits.

With Enigma set to be a box-office hit 60 years after Marie arrived at Bletchley Park, her story - and that of hundreds of others - is finally being told. But she still has no idea why she was handpicked to help change the course of the war.

'I don't think we thought what we were doing at the time was important.

There were people out there fighting, after all,' she says. 'But I'm glad I was there. They were some of the best years of my life.'

Enigma is released nationwide on September 28

©2001 Daily Record and Sunday Mail