THREE MEMBERS of the KELY circus school - David Simpson, Sean Mitchell and Lyanne To, who will act as the team's interpreter - plus a French street performer called Francois Zanini, have come to Tai Tam Gap. The school, which drew its founding inspiration from a report on the positive effects of circus schools in Northern Ireland, was set up as a KELY Support Group Initiative last year. And, lest these proceedings be accused of condescension, perhaps it should be noted here that the school makes a point of getting its weekend students to pass on their new-found skills, and the recipients are just as likely to be Goldman Sachs executives as young offenders.

Still, some adjustments have had to be made to the programme. A list of activities was faxed to the CSD six weeks before today's gathering; suffice it to say that Zanini will not be doing his amazing fire act, nor will the girls be allowed to keep the juggling balls they will make later. A watchful eye will also be kept on scissor use. But plenty of other equipment, including unicycles, plastic plates, clubs, stilts and - according to the mysterious list stuck to the side of the packing boxes - the Diablo Hummer, the Good Solid Diablo and the Beginner Hi-Fli Diablo, have made the cut.

While the performers are setting up in the Inmates-Parents Centre, a cheerful, airy annexe which was opened last March two minutes' walk from the main building, the girls are being laboriously transported round by bus. For 10 of them, this marks the first time they have stepped through the front gates since their sentences began and, as Elana Chan points out, the decision to allow them to do so is her responsibility. The gates of the compound, within which the annexe is situated, will be locked while the girls are on site. (Later, Dellow admits that while she was in England one of the inmates in her group was so impressed by the liberation of his mind and spirit that he subsequently decided to free his body too, and did a bunk.) Nice (or 'Lovely!') though it might be to write here that the girls are thrilled at the prospect of learning circus tricks, it would be an exaggeration. For a start, they have no idea what the day holds in store for them: for security reasons, they have been told only that they will be doing some unspecified activities this morning. The presence of the female prison officers is also an impediment to exuberance. Nothing, including trips to the lavatory, can be done without constant scrutiny and frisking.

When they are summoned, it is by number.

Yet there is an air of guarded (in every sense) anticipation. Although the minimum age at Tai Tam Gap is 14, some of the girls look younger, as if they should still be dallying in a playground, not in a youth prison. When Zanini lurches towards them on stilts, grinning his clown's smile, spitting on his hands and wiping his armpits, they start shrieking and clutching one another. Instinctively, they glance back at the officers to check such abandon is permitted. Later, when they start to juggle, some of them run to show their overseers the new skills they've acquired, seeking approval and praise.

The guards shout encouragement to the girls, take photographs of the activities and are not above some discreet, amused, attempts at juggling themselves. Some of them look uncannily like older versions of their charges - though without the distinguishing marks of self-mutilation worn on the wrists of a few of the girls. ('From the outside,' explains Elana Chan of the marks and referring to the world beyond Tai Tam Gap. 'That's why I have to have female guards, to check their bodies. I've seen a girl with horrible cigarette burns, poor little thing, her boyfriend was a pimp. Oh, I've seen the darker side of society.') The activities chosen by the KELY group - assembling blocks of Lego, learning to fall into one another's arms, balancing on unicycles - are clearly about trust and team spirit. In a perfect world, within this imperfect setting, all the performers would be able to speak Cantonese. But they can't. Zanini's little jokes delivered from on high ('You're very sweaty, eh? Non, non, I mean sweetie') sail over the girls' heads. Even with a super-abundance of goodwill and mime skills, the barrier is not just the locked gates: it's language. 'I do miss the rapport of being able to chat to these kids,' sighs Dellow, with genuine regret. 'Just to be able to say, 'I do like your haircut', or to have them say to me, 'Oooh, you look like my auntie'...' Naturally, the girls gravitate towards Lyanne To, chatting to her while they make juggling balls out of rice stuffed into stockings. (One wit, with possible aspirations to a further life of crime, immediately pulls the stocking over her face, to the giggling, hand-covering-mouth, amusement of her companions.) They ask To for details about the KELY circus school for when they get out, they say they'd like to show their brothers and sisters the tricks they're learning and, unexpectedly but touchingly, they check a few English phrases with her so they can repeat them to Zanini and Mitchell. They have a yearning to communicate with these strangers from another world.

AFTER AN EXCELLENT lunch, cooked by inmates who are studying catering and which included the famous Tai Tam Gap cheesecake that has, as Chan proudly pointed out, 'been admired by Mrs Tung, our chief executive's wife', Dellow sets off for Cape Collinson Correctional Institution. In theory, it is not far from Tai Tam Gap, but because of the one-way system she has to do a huge loop through Chai Wan to get there.

And so it is with the afternoon's workshop: in theory, it's not too different from the morning session but in practice, the sessions are a long way apart.

When the colonial government picked locations for its prisons and detention centres, it tended, for obvious reasons, to favour remote spots. As a result, such places usually offer exceptional views and Cape Collinson, located on the edge of the sea, is stunning. There are 150 boys there, aged 14 to 17, all of whom are detained under the Training Centre Ordinance; three of them have committed manslaughter. The parade ground, where a group of 25 boys are being marched in for the afternoon session, echoes to another, more peculiar, colonial legacy: although it is doubtful if any non-Cantonese speakers now work in the institution, English drill terms ('Attention!' 'As you were!' 'Eyes right!') are still employed by the CSD officers.

Going into a teenage boys' institution is a more tricky business than visiting a girls' centre. The first time Dellow went to Lai King Training Centre, a guard asked her to do up the top buttons on her shirt which, he felt, were gaping in a troubling manner. The air, it seemed, was thick with turbulent hormones.

Today, Dellow has organised three drummers from a group called The World Beats, which does educational workshops in Hong Kong, but the one man of the trio, Mamadou, has dropped out at the last minute. (His spiritual adviser in Senegal warned him of dire consequences if he played his drums in a prison.) This leaves two women, Kumi Masunaga from Japan and Hilda Ho from Singapore, to conduct the sessions.

It is quickly apparent that the boys are, at best, wary of such proceedings and, at worst, covertly hostile. They hide their heads behind their bare knees (where tattoos occasionally put in an appearance, swirling from beneath their regulation shorts), they snigger, they sigh, they wince with self-consciousness. The photographer is asked to stop shooting. To be fair, most youths would react the same way, adolescent inhibitions not being confined to those in custody. But the dazzlingly hot parade ground, the hovering prison officers and the two slender girls, beating drums clasped between their knees, form the ingredients of a particularly complicated brew.

Still, Masunaga does her best to chivvy things along. And at least half the boys are willing to try out her rhythms, using chopsticks on a variety of instruments - water bottles filled with lentils, buckets, oil cans, African drums. Some inmates look as if they're inflicting grievous bodily harm on their chosen surfaces, but Dellow, an optimistic, glass-half-full kind of woman, says later, 'They were making music, and that's the most important thing.' The group is also encouraged to dance, using sweeping gestures, skips and wriggles, in a conga line around the ground. This is exactly the kind of activity to which Mamadou, being male and African, could have brought some street credibility. It's hard for the boys to be enthusiastic about Masunaga's instructions, but some of them do loosen up enough to give it a go and by the end of the session, there are more smiles than there were at the beginning. Immediately afterwards, there is another session which, Masunaga later reports, is the best of the day: the boys really get into the whole rhythm and have a 'great' workshop.

By that time, Dellow is already on her way back to Tai Tam Gap, where the girls are out in the compound, juggling, plate-spinning and unicycling. The transformation from the initial solemnity of the morning to such happy chatter is astonishing. Dellow, delighted, says, 'It gives me such a buzz, doing these programmes. You just think, Why would you want to sit in an office all day? Working with kids is such a joy. Their sense of fun should have been lost, they're in prison, but it's still there. It's such a treasure and we lose it as adults.' The irrepressible Chan, too, is pleased with how the day has gone. She wants to see more Beyond Bars sessions at Tai Tam Gap ('The team-building and rapport is most valuable, I want this to happen more frequently and, you know, Sally, there's no such thing as a free lunch!'), but it's a question of finance. Dellow pays everyone involved in the prison workshops, even if it's just a nominal fee. 'And the Youth Arts Festival doesn't have the money to keep me doing this all year round,' she explains. 'The CSD doesn't have the budget either. There's a million-and-one ways we could spend money developing this programme. But it would take a special sponsor to fund it. There's little publicity in it, it's not something you'd do for a huge number of column inches.' As the November light fades, and the girls fall into line and clamber back onto the bus, with its barred windows, to travel the long way round the short distance to the main gate, David Simpson comes over. 'That was brilliant at the end,' he enthuses. 'They really got into it. They must have said 'bye-bye' about 50 times.' 'But it always makes me want to cry when they go back into prison,' says Dellow, half-laughing at herself. 'And it also makes me feel that at last I'm putting something back in to Hong Kong, even though I can't speak Cantonese. That I'm not just making money or being involved in expat theatre but finally giving something in return.'