On the morning of 11 September there was a man wearing a blue tracksuit top in the Pigalle area of Paris. It's a somewhat sleazy area, known for its sex shops as much as its art nouveau connections, but this man was thinking only of the art of pickpocketing.

He looked around, as he'd been doing for a while, and spotted an obviously-touristy couple going into a café. He observed them order coffees and croissants in halting French, though he cared not for their dietary requirements or their linguistic limitations.

They moved to a table at the back of the cafe to escape the noise of road works outside. He watched as the man sat at the back facing outwards and the woman slung her handbag on the back of her chair and sat facing him with her back to the room.

After a couple of minutes the shortish swarthy man made his way to the table behind the woman and sat behind her, his back to her. He was careful to be quiet, and avoided scraping his chair on the tiled floor. Perhaps he wondered if they'd seen the sign at the till warning patrons to be careful of pickpockets. He listened as the tourist couple spoke in English, and at a point when their conversation was at a peak he casually and without turning slipped his hand into the woman's unzipped handbag. His fingers searched for the red leather purse he'd watched her use at the counter, found it, and deftly withdrew it from the bag, slipping it into his tracksuit pocket.

He got up and left without haste. Nobody noticed him go. He was the invisible man.

Five minutes later Liz and I finished our croissants and coffee and got up to leave. Liz, as usual, checked her bag and discovered her wallet was missing. It took only seconds to realise that the man in the tracksuit top sitting behind her had taken it. It couldn't have been anyone else - the cafe was basically empty, and there was nobody else nearby.

As happens in situations like this, you go through shock initially, then try to think what was in the wallet, then what to do about it. We alerted the people behind the counter and they called the manager from the back. We explained as best we could what had happened. Liz pointed to the security cameras on the ceiling and asked if he perhaps had footage. The manager said he did. The police were called, and the boss went off to check the video recording.

I, meanwhile, went outside, having decided that the thief would most likely ditch the purse after ransacking it for anything valuable. He would have found only two Euros in loose change and eight single metro tickets, but also Liz's New Zealand and English credit cards, and her driver's licence. I looked in five nearby rubbish bins, thoughtfully provided in clear plastic by the Paris city council, but found nothing. On returning to the café I found Liz surrounded by three police officers on their bicycles. One went into the cafè, one disappeared on his bike and the other took details from Liz. They were all devastatingly handsome, and armed (which I thought was a good thing, and hoped for the thief to be spotted fleeing, then falling in a hail of bullets...)

The security image of the voleur turned out to be very clear, so while the handsomest cop continued talking with Liz and me the other two fliks cycled off to check out the area.

To cut to the chase, there wasn't one. No chase down the main street of the 18th arrondisement, no leaping off bicycles and pinning the suspect to the pavement, and no French S.W.A.T. team with snipers and megaphones. But the three cops did well and took the situation seriously. They even seemed to know who the suspect was, and confirmed he was a professional.

We were advised to make a 'complaint' at a nearby police station for insurance purposes, so, leaving the pedalling policemen to the task of running the scumbag to ground, Liz and I trudged to the local constabulary, where we were turned away and sent to another one not far away where, we were assured, there were more staff and they spoke English.

It was at this point the circumstances took a bizarre twist. We went into the police station and up to the counter staffed by a woman in civilian clothes and a young policeman in uniform. I said in French that we were sorry but we didn't speak French very well and that maybe they had someone there who spoke English. The young French cop, whose name turned out to be Olivier, then said that I spoke very good French, that he could understand me perfectly and that I should make my declaration/complaint in French.

I protested that the circumstances were such that English would be easier for us, but again he congratulated me on my French, saying that the only way to learn French was to use it. I agreed, in principle, but managed to persuade him that his English sounded much better than my French. I must have made an arresting case because he in turn reluctantly agreed and asked us to wait for a few minutes on the bench nearby.

He then appeared from around the counter and whispered, 'I will be with you in just a few minutes, but first I must go outside for a cigarette.'

What could we say? It was so amusing all we could do was agree, and in fact he was back within about four minutes. I said 'Vous fumez trés vite' which he agreed was the case, and again complimented me on my French. Tchah. Let's get on with it...

Liz told him the story, he typed the whole lot into his computer (in French), read it back to us (in English, apologising for his interpretation), and printed it out for Liz to sign. Our conversation was a curious blend of Franglais, but we seemed to all cope quite well.

And that was it as far as the police were concerned. Annoyingly, our next task - advising the banks in New Zealand and England of the theft of the credit cards - was complicated by the fact that for the first time in weeks we had left our mobile on charge on the boat, and had no back-up, no phone cards, and no SIM in the iPad. So it was a worrying journey back to the boat on the metro before Liz could get on the phone and cancel the cards, but luck was with us and none of them had been used in the intervening couple of hours since the theft.

In fact, we hadn't been back on the boat more than an hour when we got a call from a French woman who spoke excellent English to tell us she had been about to throw a sandwich wrapper into a rubbish bin in the 18th arrondisement when she spotted what she called 'a nice leather purse', inside of which she'd found one of our Liberty business cards with our names and phone number on. Quel relief!

However, she confirmed there were no credit cards or driving licence, but offered to return the purse to us before we left Paris. Wonderful. We made arrangements, and Liz and I decided we deserved to at least rescue some of the day so went via the metro to the Orangerie by the Jardins de Tuillerie to view some of Monet's iconic water lily paintings. We figured it would be a nice, quiet, therapeutic thing to do - a million metaphorical miles away from sneaky scumbag thieves and sordid doings.

It was. I had never seen any of Monet's lily paintings in real life before, though Liz had been to the Orangerie many years ago, so she knew what to expect. I didn't. What grabs you at first is the sheer enormity of them - some are 12 metres long by 2 metres tall. They predate Cinemascope and curved widescreen HDTVs by decades, yet capture in glorious panorama the lilies of Giverny.

Even better, because we arrived at the museum less than an hour before closing we were charged only half the usual admission price. Which seemed appropriate given the events of the day; it was a steal.