Sitting on the plane, with no work to do and nothing to read except the 'flight magazine', I thought about it. I tried to compare this relationship with Gloria to the one I'd had with Fiona, my wife whose fortieth birthday would be coming up soon. She'd always said she dreaded her fortieth birthday. This 'dread' had begun as a sort of joke, and my response was to promise that we'd celebrate it in style. But now she'd be celebrating it in East Berlin with Russian champagne no doubt, and perhaps some caviar too. Fiona loved caviar.

Would I have got as far as London Heathrow with Fiona and still been trying to pretend that we were embarking on some madcap romantic escapade? No. But the fact of the matter was that such a romantic escapade would have had a very, very limited appeal to my wife Fiona. Wait a moment! Was that true? Surely the real reason I wouldn't have told her that this was a 'surprise getaway' was that my wife would not have believed for one instant that a sudden invitation to fly to Nice would be a romantic escapade. My wife Fiona knew me too well; that was the truth of it.

But at Nice the sun was shining, and it did not take very much to restore Gloria to her usual light-hearted self. In fact, it took no more than renting a car for our trip to the last known address of Inge Winter. At work Gloria had seen me dictating and conversing in German, and sometimes my imperfect Russian was used too. So she was ill-prepared for my halting French.

It went wrong right from the start. The beautifully coiffured young French woman at the car rental desk was understandably irritated when I tried to interpose news about my need for a car into a private conversation she was having with her female colleague. She didn't hide her irritation. She spoke rapidly and with a strong Provencal accent that I couldn't follow.

When finally I appealed to Gloria for help in translating this girl's rapid instructions about finding the vehicle, Gloria's jubilation knew no bounds. 'No compree!' she said and laughed and clapped her hands with joy.

Despite Gloria's uncooperative attitude we found the car, a small white Renault hatchback that must have been sitting in the rental car pound for many winter days, for it did not start easily.

But once away, and on to the Autoroute heading west, all was well. Gloria was laughing and I was finally persuaded that it had all been very amusing.

It was only a few minutes along the Autoroute before the Antibes exit. On this occasion, determined not to provide more laughs for Gloria I had a handful of small change ready to pay the Autoroute charge. Now, with Gloria bent low over a map, we began to thread our way through the back roads towards Grasse.

Once off the Autoroute you find another France. Here in this hilly backwater there is little sign of the ostentatious wealth that marks the coastline of the Riviera. Rolls-Royces, Cadillacs and Ferraris are here replaced by brightly painted little vans and antique Ladas that bump over the large pot-holes and splash through the ochre-coloured pools that are the legacy of steady winter rain. Here is a landscape where nothing is ever completed. Partially built houses – their innards skeletal grey blocks, fresh cement and ganglia of wiring – stand alongside half-demolished old farm buildings. Ladders, broken bidets and abandoned bath tubs mark the terraces of olive trees. Heaps of sand – eroded by the rain storms – are piled alongside bricks, sheets of galvanized metal and half-completed scaffolding. The fruit of urban squalor litters the fields where the most profitable cash crop is the maison secondaire.

But 'Le Mas des Vignes Blanches' was not such a place. Here, on the south-facing brow of a hill, there was a Prussian interlude in the Gallic landscape. The house had once been a place from which some lucky landowner surveyed his vineyards. Now the hillsides were disfigured with a pox of development, an infection inevitably rendered more virulent by the thin crescent of Mediterranean which shone pale blue beyond the next hill.

The house was surrounded with a box hedge but the white wooden gates were open, and I drove up the well-kept gravel path. The main building must have been well over a hundred years old. It wasn't the grim rectangular shape that northern landowners favoured. This was a house built for the Provencal climate, two stories with shuttered windows, vines climbing across the facade, some mature palm trees-fronds thrashing in the wind – and a gigantic cactus, pale green and still, like a huge prehensile sea creature waiting to attack.

At the back of the house I could see a cobbled courtyard, swept and scrubbed to a cleanliness that is unusual hereabouts. From the coachhouse jutted the rear ends of a big Mercedes and a pale blue BMW. Behind that there was a large garden with neatly pruned fruit trees espaliered on the walls. I noticed the lawns in particular. In this part of the world – where fierce sunshine parches the land – a well-tended lawn is the sign of eccentric foreign tastes, of a passionate concern for gardens, or wealth.

On the small secluded front terrace there was a selection of garden furniture: some fancy metal chairs arranged around a large glass-topped table and a couple of recliners. But despite the sunshine, it was not really a day for sitting outside. The wind was unrelenting, and here on the hill even the tall conifers whipped with each gust of it. Gloria turned up her collar as we stood waiting for someone to respond to the jangling bell.

The woman who answered the door was about forty years old. She was attractive looking in that honest way that country people sometimes are, a strong big-boned woman with quick intelligent eyes and greying hair that she'd done nothing to darken. 'Frau Winter?' I said.

'My name is Winter,' she said. 'But I am Ingrid.' She opened the door to us and, as if needing something to say, added, 'It is confusing that I have the same initial as my mother.' Having noted our cheap rented car, she gave all her attention to Gloria and was no doubt trying to guess our relationship. 'You want Mama. Are you Mr Samson?' Her English was excellent, with an edge of accent that was more German than French. Her dress was a green, floral-patterned Liberty fabric cut to an old-fashioned design with lacy white high collar and cuffs. It was hard to know whether she was poor and out of style, or whether she was following the trendy ideas that are de rigueur at smart dinner parties in big towns.

'That's right,' I said. I'd written to say that I was an old friend of Lisl, a writer, researching for a book that was to be set in Berlin before the war. Since I would be in the neighbourhood, I wondered if she would allow me to visit her and perhaps share some of her memories. There had been no reply to the letter. Perhaps they were hoping that I wouldn't show up.

'Let me take your coats. It's so cold today. Usually at this time of year we are lunching outside.' Her nails were short and cared for but her hands were reddened as if with housework. There was an expensive-looking wristwatch and some gold rings and a bracelet but no wedding ring.

I murmured some banalities about the winters getting colder each year, while she got a better look at us. So there was a daughter. She didn't look anything like Lisl, but I remembered seeing an old photo of Lisl's mother in a large hat and a long dress with leg-of-mutton sleeves: she was a big woman too. 'How is your mother?' I asked while Gloria took the opportunity to look at herself in the hall mirror and tease her hair out with her fingertips.

'She goes up and down, Mr Samson. Today is one of her better days. But I must ask you not to stay too long. She gets tired.'

'Of course.'

We went into the large drawing room. Several big radiators kept the room warm despite large windows that provided a view of the front lawn. The floor was of the red tile that is common in this region; here and there some patterned carpets were arranged. On the wall there was one big painting that dominated the room. It was a typical eighteenth-century battle scene; handsome officers in bright uniforms sat on prancing chargers and waved swords, while far away serried ranks of stunted anonymous figures were killing each other in the smoke. Two white sofas and a couple of matching armchairs were arranged at one end of the room and an old woman in a plain black dress sat in the ugly sort of high chair from which people with stiff joints find it possible to get up.