You can get lost backstage at the Royal Albert Hall, particularly when it's infested with rehearsing circus performers. I'm hunting for Andrew Watson, Artistic Director of French-Canadian surrealist extravaganza Cirque du Soleil, but this may as well be Narnia.

Blundering past a sign saying Schoolroom, I back into two large metal swans, then surface in the auditorium where, above a steel dome, a trapeze artist with bandaged calves soars toward the royal boxes while her trainer demands, "Look up, Carole! This is not the big top - the audience is above you." In the artists' canteen, amid a babble of languages, subtly muscled sylphs load plates with bean shoots and grains, the strongman ploughs through a Desperate-Dan-sized helping of cow pie and, at a table crammed with international road crew, a Brit explains the native cuisine - "This is called a chip buttie, it's a delicacy in our country".

There's a feeling of calm, but the tension over the company's latest show, Alegrķa, is building, and Andrew Watson, when he appears, couldn't be a more suitable backstage ringmaster. Looking far younger than his 38 years, and sporting leather jeans, punky T-shirt, Lennon specs and a number-one cut, Watson's job is to shepherd a travelling village of 150 performers and technicians, 800 tons of equipment and 42 trailers across Europe and conjure in each venue a breathtaking show, tickets for which -and they're pricey - sell out within days. It's Watson who maintains the vision which, during last year's Saltimbanco, brought a dazzled audience repeatedly to its feet. He grins fiendishly: "I've seen people caught midway through a clap, their mouth open, or tears streaming down their face."

It's hard to explain how this works, but the Cirque operates on a dangerous, esoteric plane which puts the viewer on an emotional highwire. Forget Nellie the elephant (no animal acts here), this is New Circus, hallucinogenic - "High-grade dope!" roared one Dutch headline - and cathartic. Saltimbanco was a full-frontal assault: sensitive clowns; a tiny child, curving his body while balanced in his mother's palm atop a 40 ft human pyramid; two aerial flyers who caress at altitude and then execute death-defying swoops with knowing smiles. More than the pyrotechnics, what is moving is the grace, humour and trust of artists who put their lives in each other's hands. ("You, a journalist, cried?" asks Watson, frowning sympathetically. "Maybe because it's something lacking in our society, people trusting each other. Of course, the emotions transmitted are ones you experience anyway - it's just that you're flooded with them." Quite. Let's get on.) Every year, thousands try to run away and join up, though that's to miss the point, since the company's rather Zen philosophy is that anyone can have a Technicolor life. Take Zen or leave it, but Cirque du Soleil makes cynicism very tricky. Certainly, do not attempt it with Watson, who at 18 walked out of a sales rep job in Park Royal, South Wales, to audition for circus maestro Gerry Cottle. "I said, Gerry, I can't do anything, but just give me a chance and one day I'll be able to." Cottle had Watson and his partner trained up into internationally successful trapeze artistes who were spotted and recruited by Cirque, which itself has grown prodigiously over the last 10 years, from a handful of street performers and stilt-walkers into a $30 million industry employing 1,250 performers on three continents.

Ask Watson why he switched from performing to his current job and he'll tell you his back was "feeling the effects" of cradle work. More precisely, his partner, Jacqueline Williams, fell from the trapeze during a show; working without a safety harness, she smashed her pelvis and both wrists. "What went through my head after thousands of performances was, `It's happened'." Circus is danger, says Watson, and everyone will fall, but these days he insists on harnesses, a travelling medical team, ambulances on standby "and in each city we have contacts for the specialists we'd need in case of emergency or to refer someone for whatever's happening with their body". Still, there's no real insurance. Recently, a performer broke three ribs during a flying act. "It doesn't happen often, but it happens fast."

Confidence comes from training, precision and commitment. There's also what Watson calls "heart", an intensity equal to Method acting. British Olympic gymnast Paul Bowler debuts with Alegria as Cube Man, his prop a 5 ft square of tubular steel which he manipulates 30 feet in the air. Bowler has said his biggest lesson was to express himself emotionally, and Watson agrees. "You can be great choreographically but, unless you transmit to people, it can be rather cold. I know, with Paul, he's got it. He's very human."

Hippy schtick perhaps, but it's this notion of humanity that allows such a vast commercial enterprise to remain true to its origins. Watson will explain the concept. "You have the dome, its heavy arches, very solid and difficult to move, like a royal court. We thought, if the king should disappear, the fools and jesters would take over, and so you see youth and energy breaking through the weight of tradition, bringing beauty and contact between people." The ideal extends beyond the ring: Cirque recently established a series of projects for homeless children in Santiago, Quebec and Rio, where "kids can start to discover motivation, so they begin to believe in themselves, and they discover some hope."

"It's hard work, and not without tension. But you couldn't live, touring day to day, if you're bearing a grudge - you'd poison yourself, wouldn't you? Also, people respect each other's jobs; differences go out the window." If circus is in the blood, Andrew Watson is mainlining enthusiasm. But why not? Just now, this is the greatest show on earth.

Glyn Brown, Zen and the art of the emotional high wire, Independent, 01-05-1998, pp 1.