The cool morning air smelled clean and fresh; I took a deep breath and rubbed my smarting eyes, feeling spaced-out from lack of sleep.

Then I picked up my bag and turned to the house.

It was a well-travelled country, dad told us. Within the oceanic depths of time that lay beneath the surface of the present, there had been an age when, appropriately, an entire ocean had separated the rocks that would one day be called Scotland from the rocks that would one day be called England and Wales. That first union came half a billion years ago. Some of those rocks were ancient even then; two billion years and counting, and shifting and moving across the face of the planet while that primaeval ocean shrank and closed and all that would become the British Isles still lay south of the equator. Compressed and folded, the rocks that would be Scotland — by then part of the continent of Euramerica — held within their crumpled, tortuously layered cores the future shape of the land.

By a third of a billion years ago, that part of Euramerica lay on the equator, covered by great fern forests that would be buried and folded and pressed and heated and so turn to oil and coal, in the future that was yet to come. Meanwhile the mass of rocks, afloat on the molten stone beneath, were heading slowly northwards, and sundering; the climate became hot and the rains sparse; the great dinosaurs, tree-tall and house-heavy, tramped slowly through a semi-desert while a new ocean opened to the west. After the dinosaurs had gone, and while the Atlantic still grew, the volcanoes erupted, smothering the old rock on the surface under their own vast, deep oceans of lava.

The land then held mountains higher than Everest, but they were worn down eventually by nothing harder than wind and water, until, much later still — now that Scotland was level with Canada and Siberia and the earth cooler — the glaciers came, covering the rocks with their own chill, inverted image of the old and weathered lava plains. The sheer mess of that frozen water etched the mountain rock like steel engraving glass, and pressed the roots of those fire-floating hills deeper into the dense sea of magma beneath.

Then the climate changed again; the glaciers retreated and the water they had held filled the oceans, so that the waters rose and cut what would eventually be called the British Isles off from mainland Europe, while the scoured, abraded hills to the north, set free at last from that compressing weight of ice, rose slowly back out of the earth, to be colonised again by plants and animals, and people.

On walks, on day trips and holidays, he found and pointed out the signs that told of the past, deciphering the symbols written into the fabric of the land. In Gallanach, we saw the bright seam of white cretaceous sandstone that had provided the Gallanach Glass Works with raw material for a century and a half. On Arran, he showed us rocks folded like toffee, ribboned and split; on Staffa, the even, keyboard-regular columns of cooled lava; in Edinburgh, the rubble-tailed stumps of ancient volcanoes; in Glasgow, the black, petrified remains of trees three hundred million years old; in Lochaber, the parallel roads that marked the shores of lochs dammed and un-dammed by glaciers, millennia earlier; throughout Scotland we saw hanging valleys, drumlins and corries; and in the Hebrides we walked the raised beaches where the ocean swells had crashed until the land rose, and touched rocks two and a half billion years old; half as old as Earth itself; a sixth of the age of the entire universe.

Here was magic, I remember thinking, as we drove north towards Benbecula one day, looking out at the machair, gaudy with flowers. I was just old enough to grasp what dad had been telling us, but still young enough to have to think about it in childish terms. Magic. Time was Magic; and geology. Physics, chemistry; all the big, important words dad used. They were all Magic.

I sat listening to the car's engine, as we drove; mum at the wheel, dad in the passenger seat, shirt-sleeved arm out of the Volvo's window, Lewis, James and I in the back.

The car engine made a steady growling noise, and I remember thinking it was funny that those long-dead plants had been turned into the oil that had been turned into the petrol that made the car growl. I chose to forget the absence of reptiles in those carboniferous forests, and imagined that they had been populated by great dinosaurs, and that they too had fallen into the ooze, and made up part of the oil, and that the noise the car made was like the angry, bellowing growls they would have made while they were alive, as though their last dying breath, their last sound on this planet, had been saved all these millions and millions of years, to be exhaled along a little road on a little island, pushing the McHoan family north, one summer, on our holidays.

I looked out of the open window; the machair lay dazzling under the midsummer sunshine to our left.

"Prentice! Prentice! Oh, Prentice; pray for your father!"

"Hello, Uncle Hamish," I said, as Aunt Tone ushered mother and me into the bedroom where my uncle lay, propped up, splendid but demented in a pair of blue cotton pyjamas and a red silk dressing-gown decorated with blue dragons. The room was behind dim closed curtains, and smelled of apples.

"Mary! Oh, Mary," Uncle Hamish said, seeing my mother. He clasped his hands together, holding a black handkerchief. His hair was a bit mussed and he had a stubble shadow; I'd never seen him look so disarrayed. In front of him there was a huge tray with short legs, partly covered by a quarter-completed jigsaw puzzle. I walked up to the bed and put my hand out. I clutched Uncle Hatnish's still clasped hands, held them briefly, squeezed and let go.

Closer inspection revealed that Hamish was putting the jigsaw puzzle together upside-down; every cardboard flake was grey, turned the wrong way up.

Mum gave Hamish a brief hug and we sat down on a couple of chairs on either side of the bed. "I'll make some tea," Aunt Tone said, and quietly closed the door.

"And biscuits!" shouted Uncle Hamish at the closed door, and smiled broadly at first mum and then me. After a moment, though, his face seemed to collapse and he looked like he was about to weep.

The door opened again. "What's that, my dear?" Aunt Tone asked.

"Nothing," Uncle Hamish said, the mouth-only smile suddenly there again, then fading just as quickly. The door closed. Hamish peered down at the jigsaw puzzle, toyed with a couple of the pieces, looking for a place to fit them into what he had already completed. The squint bottom edge of the puzzle, some small spaces between joined pieces, a few tiny flecks of cardboard — half grey, half coloured — gathered like dust along the raised edges of the tray, and a small pair of collapsible scissors lying on the bedspread near the pillows, indicated that Uncle Hamish had — not to put too fine a point on it — been cheating.

Thank you, both, for coming," he said, absently, still fiddling with the grey pieces. He sounded bored, like he was talking to a couple of factory workers summoned to his office for some formality of business. "I appreciate it." I exchanged looks with my mother, who appeared close to tears again.

Mum had done pretty well till now; we'd both cried a bit when Ashley had deposited me at the gates of the house at Lochgair, but since then she had coped pretty well. We'd visited the good lawyer Blawke that first day, and the next day he'd actually made a house-call, a concession which, extrapolating from the attitude of his secretary when she rang us up to tell us the sacred presence was on his way, we ought to have treated with the sort of awe and respect the average person reserves for royalty and major religious figures. I was a little surprised he didn't kneel and kiss the door-step when he unfolded himself from his Merc.