In the quartier Saint-Roch, the lights from the Chateau Piquemal sparkled like the illuminations on the pier at Bognor Regis. The avenue de Sabart was lined with allotments and cabanes for the market gardeners, jostling for position with the houses that had sprung up like weeds in the quartier de la Gare. And in the mouth of the southern tip of the valley, the new factory buildings sat long and flat and squat, modern gatekeepers to the older rhythms of the mountains, reminding me of the greenhouses in the walled garden at my childhood home.

Clouds of white smoke belched from the chimneys, shot through with eerie blue or green or yellow tints from the metals they consumed. Aluminium, cobalt, copper. And in the air the smell of burning, the scent of industry. Of time marching on.

It was not possible to get inside the Tour du Castella. A small door was nailed shut, and halfway up was a blind window with a black grille across it. The weeds grew wild around the base. The grey stone was covered with moss and lichen.

Its position was vertiginous enough, though. The ground surrounding it dropped sharply away. There was no barrier or handrail, nothing to stop the intrepid traveller who had climbed this far from slipping or stepping out.

As I looked down, I felt suddenly dizzy, from the cold, the narrowness of the ledge around the foot of the tower. The vast sense of space and dusk. For an instant, I thought of how easy it would be to finish things now. To close my eyes and step out into the gentle sky. Feel nothing but air as I fell down, down into the foaming waters of the Ariège below. I thought of the revolver in my portmanteau, hidden beneath my Fair Isle slipover, a match to George’s old service Webley that I’d not been able to bring myself to use.

I had acquired the weapon in a rare moment of purpose six years ago, just before the mental collapse that had seen me confined for some months to a sanatorium. Hurrying down a Dickensian alley in the East End of London that was black with soot, the air rank with resignation, I’d made my way to an address slipped to me by one of George’s fellow officers. Simpson was a ruin of a man, drinking himself to death to escape the shame of being the only one to have made it back. So he understood, better than most, the importance of a quick and easy solution to things should the burden of living become too much. I bought that particular revolver knowing George had owned one, and, for a while, the possession of it had given me courage. But I’d funked it. I had never fired the gun. Never even loaded it.

At that instant, standing at the foot of the tower on the top of the precipitous hill in Tarascon, I felt a rush of blood to the head at the thought that perhaps the moment finally had come. Elation at the possibility of decisive action. Of joining George. But only for an instant. Then, as at every other time, the impulse slunk away with its tail between its legs. I stepped back from the ledge. Felt the safety of the stone at my back, my hands flat against the brick.

A few minutes passed until my head stopped spinning. Then I turned and descended the wide, shallow steps that led down from the mound to the streets below. Was it courage or cowardice that stopped me? Still I cannot say. Even now, I find it hard to tell those impostors one from the other.

Later, after a modest dinner in the restaurant opposite the hotel, unwilling to be alone with my thoughts, I sought out a bar in the Faubourg Sainte-Quitterie where men were prepared to accept without question a stranger into their company.

Their rough voices spoke with pride of the future of Tarascon. And as I raised a glass to the prosperity of the town, I did understand this need to move forward, to forget. How, with drums and penny whistles, the world marched on. Such swaggering industry boasted to travellers and citizens alike that there was a future there for the taking, not just tawdry memories. That the ruined landscapes of Flanders should be allowed to fade from memory. Honour the dead, yes. Remember, yes, but fare forward. Look to tomorrow. Jazz and girls with bobbed hair and those chic, false new buildings in Piccadilly. Pretend that it had all been worth it.

As the evening staggered on in a haze of red wine and strong tobacco, I have a recollection that I tried to tell my drinking companions how, in ten years, I had not learned to forget. How electric signs and teeming carriageways could not drown out the voices of those who had been lost. How the beloved dead were always there, glimpsed out of the corner of the eye. At one’s side.

But my schoolboy French meant they were spared my philosophising and besides, for all its rituals, grief is a solitary business. So the evening ended with the shaking of hands, the slap on the back. Companionship, certainly, but precious little communication.

When finally I found my bed, I was restless and wakeful. The tolling of the single bell marked the passing hours of the night. Not until the pale dawn crept through the wooden slats of the shutters did I, at last, fall into a deep and heavy sleep.

I tell you about that evening in such detail, Saurat, not because I cared so very much about this particular town. It could have been any one of a hundred places in that corner of southern France. But it is important to recount every ordinary minute so you understand that nothing about that night in Tarascon could be seen as the harbinger of what was to come. I staggered between remembrance and maudlin self-pity, which was how it was in those days. On other nights, things had been worse, and they had been better. I occupied an emotional no-man’s-land, neither moving forward, nor moving back.

But although I did not yet know it, the watcher in the hills had me in her sights. She was already there. Waiting, for me.

On The Mountain Road to Vicdessos

In the darkest days of my confinement in the sanatorium, then during my convalescence at home in Sussex, dawn was the part of the day I dreaded most. It was in those early hours that the barrenness of my existence seemed most starkly at odds with the waking world around me. The blue of the sky, the silver underside of the leaves on trees coming back to life in the spring, celandine and cow parsley in the hedgerows, all appeared to mock my dull spirits.

Looking back, the reason for my breakdown was perfectly straightforward, though it did not seem so at the time. To those around me, to my parents certainly, it was peculiar – in bad taste, almost – to have waited so long before going to pieces. It was not until six years after George’s death that my battered mind gave up the fight, though in truth it had been a steady deterioration.

We were at a restaurant not far from Fortnum & Mason’s to celebrate a. my twenty-first birthday. I can still remember the taste of the Montebello 1915 champagne on my tongue, the same vintage, as it happens, Fortnum’s had provided for the Everest expedition that year. But as we sat there in a brittle silence, Father and Mother and I, George was a shadow at our table. It was his presence that had made us a family. He had been the glue. Without him, we were three strangers with nothing to say. And here I was, the other son, sipping champagne and opening gifts, when George had never even reached his majority. It was wrong.

All wrong.

Was I the elder brother now, having lived longer than George? Had we exchanged places? Such thoughts, becoming ever more heated, spun round and round in my mind. The waiters glided past us in black and white. The bubbles of the champagne scratched at the back of my throat. The clatter of cutlery grated on my nerves.