That summer was the record-breaking one. Back at Tair-Ffynnon, it seemed as if clouds had become extinct. Exchanging our hard-won London pad for a derelict hilltop smallholding seemed the cleverest move we’d ever made. We bought a big army frame tent (big enough to accommodate a Land Rover) to act as a spare room for friends to stay in. It came in two vast canvas bags, so heavy the delivery driver and I could only just move them. The military instructions specified at least five to erect it (‘pitching party—five men’) so we did it one day when friends came for lunch. We weighted the wide ‘mud cloths’ with concrete joists and breezeblocks and whacked in two dozen enormous iron pegs with a sledgehammer. Then, inside, we decked it out, until, frankly, it was the cosiest room about the place.

      We’d got a new black Labrador puppy (christened Beetle after her propensity for eating dung) and twice a day I’d walk up to the trig point with her. The place bustled with activity. During the day there were walkers and riders, bemused school orienteering parties, pony trekkers, runners, mountain bikers, radio modellers, occasional motocross riders (on plateless scrambling bikes and always careful not to remove their helmets). Gliders would fly down the ridge, almost brushing the bracken, so close you could hear the air rushing over their wings. There were falconers, racehorses exercising from the local yard, whinberry pickers with faces and fingers stained purple-black. Walkers would stop to ask for water, or, exhausted, if we could drive them to their B&B. And when we heard muffled shouts and bright canopies billowed up on the far side of dry-stone walls, we’d know the wind was from the east. Then dangling figures suddenly appearing out of the sky would drive Beetle into paroxysms of territorial barking, a remit she soon extended to anyone wearing a backpack, rendering our walks a good deal less relaxing for all concerned.

      But as evening came, calm would descend; the hill would empty, until the moment when it was deserted apart from the swallows. After all the bustle, the quiet seemed twice as intense. Day after day dawned cloudless and warm, some so clear and still that, in the way that silence amplifies space, the sky seemed twice the size. Far above us, vapour trails dispersed like gradations on some vast protractor. Stonechats arrived, their characteristic call like two stones smacking together. At ground level, the forests of thistles left by the sheep went to seed, sometimes filling the air with so much thistledown it seemed to be snowing. A red start nested in the baler. As the hill got drier and drier, the ponies brought their foals to drink at the bathtub in the yard.

      October brought the first serious hill fog. We were used to inter mittent fogs lasting the morning, shifting with the wind which interrupted their opaque evenness, perhaps affording a glimpse of the shining white disc of the sun, or offering fleeting vignettes of things made strange by the randomness of their selection—a wind-blown thorn tree singled out from the hill across the valley, a distant farm, the top of Skirrid or Sugar Loaf. Occasionally a confused-looking pigeon or crow might make us feel momentarily less alone. Usually these fogs burnt off during the morning, but this one was different. It arrived one Sunday when our friends Nick and Kate were staying. Kate, who was pregnant, went out for a ten-minute stroll, only for dense cloud to sweep across the hill. When after an hour she hadn’t returned and twenty minutes of bawling her name into the murk met with no response, we began to worry. What made it worse was Kate was a byword for self-reliant competence. Another hour later, neighbours just the field below us called to say she’d found them, having lost the path and stumbled over tussocky moor, scrambling over five foot walls and barbed wire fences in her desperation to find civilisation. We sensed, as Nick and Kate’s red tail lights faded into the gloom, that they left few regrets behind them in the fog, now denser than ever.

      Next morning it was still there, deadening everything. Usually, depending on the wind direction, the sound of tractors, farmers calling dogs, chainsaws or even the railway were audible from the valley below. But not now. We could hear nothing. By Tuesday the oppressive atmosphere had begun to affect us; we were getting on each other’s nerves and taking headache remedies. Escaping to walk Beetle, usually the best remedy for every irritation, brought no relief; indeed, it seemed to compound the problem, confirming the impossibility of escape, while the heavy air made me breathless and left my clothes damp. We would compete for the chance to go down the hill, once we’d discovered the fog stopped at the hill gate and life seemed to be carrying on as normal down there.

      After four and a half days, I opened the bedroom curtains and stood blinking. The fog had gone. No, that wasn’t strictly correct: it had moved. It was below us. Now we, Skirrid and Sugar Loaf occupied a lofty world above the clouds. Tendrils of water vapour lapped at the yard gate, sometimes reaching up as far as the front door, like waves on an incoming tide. Occasionally, the mist would rise up and engulf us completely, then sink back down again, the water vapour sliding off the roof of the house and rolling round the yard, as the first pink shafts of the rising sun broke over the roiling sea of cloud. We pulled on our clothes and walked to where the hang-gliders launched, then climbed the hill in the chilly stillness, to see how far this ocean extended. Over the entire world, it seemed.