Worlds apart

LONG before 9/11, as a new film shows, the Twin Towers were the scene of an astonishing act of 'art terrorism'.

A SMALL BUT ENERGISED CELL OF individuals, distinguishable from their neighbours only by the otherness of their accents, pile out of their brownstone apartment building in New York. They start loading equipment into the back of a van parked at the kerbside, taking care to shield their specialised cargo from prying eyes. Left scattered around the apartment are architectural plans, blueprints, notebooks filled from cover to cover with engineering data, and detailed sketches of one of the city's most prominent landmarks.

As the last passenger jumps in and the van sets off for its destination, phoney ID cards are handed out, disguises readied, and nervous rumblings heard. Some of those present are unsure about their preparation and, beyond that, the very nature of what they are embarking upon. The young man in the front seat, however, is altogether more confident. He knows that, if successful, the mission will have the greatest impact imaginable – and that his work that day, which will take him less than an hour to complete, will be spoken about for years to come.

This isn't the prelude to Hollywood's latest "war on terror" opus; rather, they form the opening images of an altogether more affirmative and remarkable documentary which – having won the World Cinema Jury and Audience awards at Sundance in January – will receive its European premiere at Edinburgh in June. James Marsh's Man on Wire describes how Philippe Petit, a street entertainer and self- described "little climber" from Paris, came to walk a tightrope suspended between the twin towers of the World Trade Center on 7 August, 1974, just over a year after the buildings had opened.

It was the funambulist's latest coup de théâtre after similar (and similarly illegal) assaults on Notre Dame and the Sydney Harbour Bridge, and the spectacular climax of an obsession sparked when Petit read about the Towers in a magazine in a dentist's waiting room. Speaking from New York, where he and Marsh are promoting the film, Petit reveals how even his nagging toothache had to be put on hold when he saw the Towers for the first time: "I started to dream about putting a wire there one day. I ran out of the waiting room with my treasured article, and then I had to find another dentist."

The walk required months of planning. Petit entered the Trade Center dressed as a businessman, figuring out the best time for him to sneak back in with his equipment. He hired a helicopter with a co-conspirator and flew over the Towers. At one point he posed as a journalist from an architectural publication to interview construction workers employed on the building's upper levels. Getting on to the roof required hiding under a tarpaulin for several hours while security passed by. For some, it was a breach too far: the walk was variously reported as "the artistic crime of the century" and "art terrorism".

In a post-9/11 world, it's impossible to watch Marsh's film without seeing signs of things to come. Archive footage of the building's construction – men in hard hats milling around a hole at what was later to be Ground Zero; the Towers' long metal slats heading upwards, rather than down – contains uncanny echoes of its destruction. Yet at the same time it's hard to imagine al-Qaeda running a training camp as bucolic as Petit's: tucked away in the greenest French countryside, with hand-painted signs and Philippe's friends and lovers jumping up and down on the tightrope wire in an attempt to simulate the effect of high winds on the walker.

Marsh's film stops at the point where Petit was apprehended by somewhat baffled cops – the film's title derives from a terse entry on the official arrest report – and chooses not to follow the historical throughline to the destruction of the Towers, recognising that the tightrope walk retains considerable fascination in itself. "It would have been wrong of me to burden Philippe's story with what happened 30 years on," the director says. "My objective was to celebrate Philippe's performance and those buildings, to – just for a little while – reclaim the memory of them for something else."

A skinny, clownish sprite – in a feature film, he'd be played by Delicatessen's Dominique Pinon – Petit tends to understate the psychological aspects of high-wire walking. ("You have to take it very seriously," is the most Marsh draws from him in the film.) I ask him what was going through his mind when he first set foot on the tightrope that day. "I had been dreaming of that walk for six and a half years, and I had been planning it for months and months, so when I found myself at the moment of the first step, it was not a surprise," he says. "It was the opposite: something I had been waiting for all my life. I was elated and almost impatient to perform that day."

He had, surely, to have been in possession of both balls of steel and trousers of Teflon. Petit didn't merely walk across the tightrope that day; he staged a full 45-minute performance, kneeling and at one point lying down on the wire, studying the crowds gathering 450 metres below ("I felt I could hear them talk"). Then – as though for an encore – he teased the police officers waiting for him on the opposite tower by evading their stretched arms and running back out over thin air.

"For me," says Marsh, "that's the point where the story becomes absolutely irresistible. The reality of it already has so many rich details, but once the police arrive, telling him he's got to come in, these angry New York cops barking at this French guy with loudhailers, and he's doing the opposite – he's taunting them. It's just wonderful, that. If a policeman stops you in the street and says, "Show me your ID," they don't expect to have to wait 45 minutes for you to get it out."

Few, indeed, have dared thumb their nose at the authorities at such a height. With a flourish of cherishable cheekiness, one of Petit's first acts after his arrest was to point out to police how security within the Trade Center complex might be improved. It wasn't the little man's only victory over those in positions of power. The walk overshadowed news of Nixon's resignation the following day, causing the outgoing president to remark ruefully at a press conference: "I wish I had the publicity that Frenchman had."

Overnight, Petit had become something of a folk hero, but he simply wasn't the type to cash in on his success. "I had not prepared for the response," he says. "I had been performing in a naïve, artistic way, so to have all America dive on me just a few hours after my walk ... I didn't know what to say. I didn't even know the word 'commercial'." A good thing, you might say. He turned down an offer from Burger King to walk a tightrope dressed as a Whopper, and continued to earn a living writing and performing. His story has since been immortalised on stage and in a children's book, and inspired a piece in Paul Auster's The Red Notebook. He was working on his own memoir, To Reach the Clouds, when the Towers came down.

When I ask what he felt on that September morning, he replies wistfully, "You can imagine: in a way, I fell in love (with the Towers]. I had a whole relationship with them, and they were very much alive to me." Both he and his director will visit Edinburgh for the film festival, and I suggest that the grand old architecture of the capital might re-ignite his passions. He perks up: "I would love to get up in the skies over there! It's up to you guys to propose where."

Here, then, is someone for whom all the world really is a stage or canvas. As his ex-girlfriend Annie Allix puts it in the film, "Every day is like a work of art to him." Watching the clips of Petit at work on the wire – centred, sure-footed, outwardly serene in what he's doing – you wonder whether the Twin Towers walk wasn't his very own Sistine Chapel moment: the point at which one man touched the heavens, leaving behind a spectacle the rest of us will continue to look up, gasp and wonder at.

• Man on Wire will screen on 26 June at 8:30pm and 27 June at 9:30pm, both at cineworld.