Saturday Story: The modern Huckleberry Finns: young runaways are fleeing school, parents and boredom. Not all come back

We should not be too surprised when kids do a bunk, and head for the bright lights. After all, children's literature is full of such adventure, tales of those setting off heroically with their spotted handkerchiefs on the end of a stick. Think of Tom Sawyer and Huckleberry Finn hiding out on Jackson's Island to escape Injun Joe and the nagging of Aunt Polly. Oliver Twist ran away to escape life as an undertaker's apprenticeship and nights spent sleeping in a coffin.

More recently, Terence Blacker's Nineties novel, Homebird, tells the tale of a 13-year-old who, underachieving at boarding school, escapes only to find his parents' marriage in trouble, So he runs and runs. Tony Blair himself has revealed that he ran away from boarding school at 13, ending up at Newcastle airport, where only the lack of international flights dashed his hopes of stowing away to Bermuda.

So teenagers are not short of adventurous example. Yet even these stories offer cautionary hints of the potential horrors facing runaways. Huck Finn and Tom return home to find their funeral in progress. Oliver ends up friends with the Artful Dodger and in the clutches o Fagin.

The teenagers in Melvin Burgess's controversial, award-winning novel, Junk, exist in a dark world of heroin addiction. Terence Blacker's runaway finds bleak refuge in a squat. He says that he made his main character middle class precisely to show that even better off children can wash up on the street.

If anybody doubted him, Blacker's proposition got plenty of high-profile support from reality this week.The papers were thick with stories of middle- class children disappearing.

In retrospect, the most high-profile of these now looks almost banal as the 12-year-old in question was found the next day, unharmed. But in another case, a 17-year-old boy slept rough for weeks on the streets of London.

Consider the case of Anne Atkins, the Daily Telegraph's very Christian agony aunt, who discovered on Sunday morning that her 12-year-old daughter, Bink (Adelaide), had gone missing in London, having left a note on the kitchen table: "I'll be back soon, so don't worry about me."

Nearly 36 hours later, following a huge police search using helicopters, Bink was found. She had spent a rainy night in the local cemetery and eaten nothing more than a McDonald's large number-three meal and a cake, bought with a fiver given by a concerned passer by. Upon her return, Bink explained: "I didn't not want to be at home - I just wanted to go away for a few days. I had an overwhelming feeling of sadness, not about anything in particular, just general. It made me feel that I wanted to hide from people so they wouldn't find me."

The story of17-year-old Alex Davies is more taxing. Last week, his face stared out of the missing person's column of the Big Issue, the magazine sold by homeless people. Alex had not been seen for nearly a month and his parents, Gordon Davies, a management consultant, and his wife Catherine, an insurance manager, were desperate.

They had travelled from their Somerset home several times to scour the streets of London unsuccessfully. Last Sunday they were searching again, in Leicester Square. "I saw someone in front of us," recalled Mrs Davies. "He did not look like Alex but he was wearing a Tottenham scarf and I decided to run after him just in case.

"He was walking very quickly and it became like one of those dreams where I was running and running and did not seem to be getting anywhere. When I eventually caught up with him, I looked into this bearded face that was not Alex's, but then I recognised his eyes. he just said `Mum' and we collapsed into each other's arms in tears."

Each of the stories reveals a truth about runaways - that they are usually fleeing from something rather seeking some splendid dream.

Latterday Huckleberry Finns are exceptional. "The majority of younger people who run away are girls," said Sophie Woodforde of the National Missing Person's Helpline. "They want to be with some older bloke, whom their parents want them to stop seeing. We get a lot of people like Alex Davies running away because they are worried about school. This is a particular problem with GCSEs because of the constant pressure of course work being assessed whereas with O-levels the pressure came at the end of the year with the exam. "A lot of youngsters are trying to find their identity, trying to feel independent but have parents who are still treating them as a child. Bullying at school is another reason. Young people may leave because of stress at home, the break-up of a marriage or abuse. The trouble is that a lot of adolescents are not very good at airing their concerns so they take off rather than talking about their problems."

That said, Ms Woodforde acknowledges that there are a few adventurers left, in the children's adventure story sense. "A few children still run away with the circus," she said, recalling one case where the only photograph they had of one teenager was of him dressed up as a clown.

Some stories retain, even in their unfolding, the promised romance of running away.

Thus, this weekend, the 17-year-old lovers, Olga Cardew and Alistair Tanner, from Bryanston School in Dorset, are being brought back home after escaping to Paris for a teenage tryst. They are more in the style of Peter Kerry, the schoolboy who ran away to Malaysia using his father's passport and credit card after a row with his family.

That is one kind of runaway story. Robert Swindells wrote a very different one in Stone Cold, his 1993 novel for teenagers. It describes a group of runaways to London, who are preyed on by an former sergeant major nicknamed Shelter. His mission is to clean up the streets and he dresses himself up as a do-gooder in corduroys and sandals. Offering a bed for the night, he brings his victims back to his flat, kills them, cuts their hair, dresses them in polished shoes and buries them in a line under the floorboards, tallest to the right, shortest to the left. He calls them his Camden horizontals.

Melvin Burgess, who did considerable research on the streets before publishing Junk, says that the image of the bogeyman waiting to entice a runaway into drugs and prostitution is exaggerated. "It is," he says, "the really vulnerable kids from shit backgrounds who already have loads of problems who get picked up."

Sophie Woodforde agree. "There are real dangers but there is a community on the streets which is also on the lookout for young runaways, to protect them and make sure they are not preyed upon," she said.

The official figures reveal that the vast majority of the 100,000 people under 18 reported missing every year return home within days. Nevertheless, in London alone, more than100 teenage runaways go untraced each year.

Their families must cling on to the straws offered by another edition of the Big Issue, when the missing person's column showed a 15-year-old girl , her face still childish, with shiny blonde hair, trusting eyes and a smile for the camera. Yet the accompanying article described her as 32 years of age and 5ft 7in tall. She had been missing since 1978, when she ran away from her home in Deptford, south London. The published picture was the last one taken before she left.

At that point most people must have given her up for dead. Yet soon after that article, she was found. It emerged that today she is married with children and living in another part of the country.

She had run away after her sister had died in an accident for which she blamed herself. Seventeen years later she came back and made peace with her family and herself.

The National Missing Persons Helpline is funded solely by charitable donation. Its freephone number is 0500 700 700. Message Home is a confidential freephone number for anyone missing who wishes to say they are alive and safe: 0500 700 740.