Last Wednesday I found myself following two beautiful but tortured-looking French lovers along the Canal St. Martin, and I admit, freely eaves-dropping in to their conversation. She was telling him she had nothing else to live for without him, and she wanted to die. Now and then they would stop to kiss passionately, and he would wipe the tears that were running down her face. I don’t even think they noticed me as they stopped to sit on the steps of the Pont Dieu and, with intent looks, started discussing some kind of suicide pact. They didn’t appear to notice me, nor the video camera I was holding… nor the other fourteen people encircling them who were also silently filming them with cameras, mobile phones and Blackberries.

Ok, I admit we weren’t just a group of intensely nosy people – but in some secretly pleasing way it felt like it. We were all taking part in the Elastic City walk Les Amants du Pont Dieu, created by the film-maker Andres Andreani. Elastic City commissions artists to create walks around cities and “intends to make its audience active participants in an ongoing poetic exchange with the places we live in and visit”. Although the company is based in New York, Andreani lives in Paris and was inspired by the 1938 film Hotel du Nord to create a walk around its two main characters, Renée and Pierre, along the Canal St. Martin. All of which meant that I found myself standing on the Pont Dieu at 7pm on Wednesday evening with fourteen other would-be voyeurs, all of us dressed in black and not having a clue what to expect.

As we stood on the bridge for our briefing, the canal waters washed beneath us and the sun lowered behind lazily waving sycamore trees. Andres explained to us that we were to film these two characters, Renée and Pierre, for the duration of the event, they were to be kept constantly in shot, and we film-makers were not to utter a word. Andres looked round the ring of us standing there, fixing us intently, one by one. “Tonight, like God, we’re going to live in more than one dimension. Magic is going to happen. Each one of us will be creating our own personal film. Tonight….” he paused for effect, “tonight we’re going to make a miracle.” And, as if on cue, a puffing jogger ploughed his way through us in a fine spray of sweat. You can’t avoid joggers on the Canal St. Martin. We were about to learn that there were a whole host of other things one can’t avoid on the Canal St. Martin. Andres handed us stickers printed simply with the words ‘Elastic City’, and advised us that if anyone asked what we were doing, in order not to disrupt the filming, we were simply to hand them this sticker. By this point I think we were all starting to feel a little bit excited.

We were ready to start. Andres pointed out a couple to us sitting en terrasse in the café La Marine over the road. Of course we had not noticed them before: they were so typically French that they blended in perfectly. He, a handsome young man with wavy hair, a flung-on trench coat and a haunted look in his eyes. She was wearing knickerbockers, had thickly churning titian hair, and was smoking a Gauloise. Now we really looked at them: they were tortured, profound, meaningful. Very, very French.

As we stood in a line filming them from the other side of the road, I couldn't help thinking we probably looked like a coach-load of goth tourists. Renée and Pierre left the café and approached the canal. We took our cue and proceeded to follow them in a pack, like very well-mannered paparazzi, as they started to walk down the edge of the canal. With fourteen pairs of eyes and fourteen view-finders trained on them, their life became the only thing that existed for us. Our lives were subsumed in theirs. I suddenly heard a stifled cry and a clatter of footsteps as one of us tripped over a big iron canal ring. The couple had started to argue and Pierre suddenly yelled “Putain!” A couple of young girls sitting on the edge of canal sniggered. A middle-aged woman stepped back and stared at us, “Mais, euh, c’est quoi, ça?”

It was here that the event really took flight – it flowered and I saw all the wonderful angles and dimensions that this kind of show opened out to us. We were filming a love story, and although we knew we were, the hundreds of people that we passed along the Canal St. Martin over the next hour didn’t have a clue. They knew nothing, except what they could see: a couple pouting, arguing, kissing, going slightly crazy, tearing away from one another and chasing… that and a troupe of stumbling people following them around with cameras. At first glance it must have looked to outsiders as though it was a film set that had been organised by a hugely inept Producer: minimal props, few previous rehearsals, and instead of booking two cameramen he’d accidentally booked fifteen. But it was absolutely fantastic. We were filming something fake but which, by virtue of us filming it, had become real – a passionate meeting between two lovers, but set to a backdrop that I already knew from my everyday existence. There outside the Super U Pierre held Renée's waist as he stared in to her sultry eyes, and after he showed her the pistol in its doorway, the Valmy cycle shop had never been imbued with so much meaning.

Because everyday life was carrying on around the couple, the story was tinged with the comic at the same time as being firmly anchored in reality. As Renée panted against Pierre’s heaving chest, a gang of slightly overweight men walked past in shot, their beer bottles clinking in blue plastic bags. At moments Pierre’s declarations of love were drowned out by a yowling police siren, or by the squealing brakes of a Latvian tourist coach as it hove in to view behind the tear-stained lovers. Todd Shalom, the founder of Elastic City, points out that the purpose of the walks is to really notice the place we’re in, and it’s true – by focusing on a ‘false’ acted story, that is not part of the canal, it made me acutely aware of all the real things going on around us. When you are privy to a heartfelt moment between two star-crossed lovers, I challenge you not to notice when two men decide to cool off by dive-bombing naked in to the canal right behind them.

For me the most fascinating and unforeseen part of the whole event was the reaction of the people on the canal to what was going on. What our couple were doing and saying wasn’t particularly interesting in itself, but outside of our small group, there were hundreds of other spectators watching us. Some were bemused, some smilingly enchanted, some ill at ease. In the background of our films we caught people striding fiercely past us, or else walking in to shot, then hesitating and looking to edge out again so as not to disturb whatever this thing is. We were even followed by a woman who started filming us filming the actors, and of course, this being the Canal St. Martin, for a brief period we attracted a shouting drunk, although he got distracted pretty quickly and moved off.

Halfway through the filming the emotionally overwrought Renée got a bit unhinged, and leapt on to the canal edge, whooping “Regarde!” And they did. Hair twirling around her, milky breasts bouncing in her silk camisole, she was a captivating sight. She was upset, desperate: she patted men’s heads, asked them Wasn’t life unfair?, skipped over legs and cat-called. Pierre grabbed her to him and clutched her wildly, hissing through gritted teeth that she should get a hold of herself. I shot a glance over my camera screen and saw the entire length of the canal in their wake was watching them. I now understood why we’d been given the Elastic City stickers at the beginning: what fantastic publicity. We had been given one each but I could easily have handed out forty. This mysterious show was also its own arresting advertising.

In the end it became difficult to know what was real and what was false. One man started doing backflips and handstands around us, deliberately trying to get in shot, and I mentally cursed him for trying to steal the limelight from our two actors. Speaking to Andres afterwards, however, it turned out that this acrobat was someone they had actually enlisted to take part in the event, although they hadn’t been sure whether he would actually turn up or not. Likewise a busker on the bridge that Renée and Pierre stopped to watch, singing and playing the guitar, was a woman that that Andres had discovered a few weeks previously… doing just that. She was a real busker rather than an actress playing a busker. Her music seeped in and out of the footage exactly like the soundtrack to a real film. And at one point, while Pierre was shouting at picnicking locals to stop staring at him, further down the canal I could hear another man bawling about something or other (when you’re going crazy there’s a lot of competition on the Canal St. Martin). All of which provided a lovely interlooping sense that all the things that were staged on this walk, could be – and were – at the same time also completely true.

Clearly Andres was inspired by the beauty and character of the Canal St. Martin, and in setting one story there, he unlocked many others – real stories, of the people who genuinely lived there. He also invoked the passionate romance that is still inherent in Paris, but which is unfortunately all too easy to forget amongst the canal’s leg-cocking dogs and over-priced beer. As the sun set on another glorious day in Paris, it was clear Andres had chosen one of the most beautiful, live, backdrops for a film theatre walk. I spent a wonderful evening that not only unleashed the inner film-maker in me, but made me see Paris with fresh eyes. Elastic City’s walks build communities between people who have never met before, and Andres’ inspired story transplanted fiction firmly, and in the flesh, in to the real world.

To see the finished film, and probably numerous shots of the back of my head, please visit the Elastic City site: www.elastic-city.org