You know the trees I mean. On that first deep stretch of the A30 heading west, after the tawny shoulders of Dartmoor have fallen behind; the stretch that always seems longer than you remembered, though it’s hard to keep the needle from nudging towards ninety. 

And then, just as you begin to despair of ever getting through the billowing infinity of Devon, there they are: a spinney of slender beeches, slewed off the crown of a small rise where the dual carriageway bends to the right. They look like the remnants of an army, a last centuria at bay. And as they whip past on the passenger side you know that inside of three minutes you’ll be barrelling across the Tamar and up the rise onto home ground. 

There are other way-markers, of course, multiplying and diverging as we swing left and right off the grand trunk, narrowing to the tendrils of the purely personal. I have some eighty miles of them still to go: the point where the western half of Cornwall opens ahead on the edge of the clay country; the rough gauge of current tide times with a rightward glance at Hayle; the wind-whipped blackthorn on the hedge at Bull’s View; and the final rise from the Mên-an-Tol lay-by to the point where the ocean opens ahead. 

But the trees are the first. A rousing signal: almost home. You might make some flashing obeisance to them as you pass, or at very least offer a nod of acknowledgment. And three miles outside of Cornwall, they are common to every traveller who crosses the Tamar. 

 * 

On a heavy August afternoon, heading homewards, I finally did something I’ve long been minded to do: at the first distant glimpse of the trees I swung south off the A30, pulled in at the side of a quiet road, unfolded the map, and tried to work out how to reach them. 

The trees, I believe, are known as Cookworthy Knapp, but the Ordnance Survey gave them no name. This was the cause of a small outrage. I felt that they should be marked with some portentous symbol – a pair of crossed flags, perhaps, of the sort that guidebooks use to show international border crossings. But they were scarcely even present on the sheet: the smallest dab of green, sitting on the 120-metre contour line and containing a single non-coniferous tree and seven miniscule scratchings suggesting some kind of pit. And to get to them, I would have to go the long way around. 

This was Devon at its deepest. The knapped blue lanes seemed to have fallen, ten, twenty, thirty feet down into the clammy base layers of a blanketing jungle. The contours were as convoluted as those of a human brain, but there wasn’t a single hard edge to knock against. Once or twice I saw the trees, suddenly leaping into distant view across the groundswell of the country, as distinctive from this side as from the other. They’d chosen their defensive spot well: I had little chance of creeping up on them. 

A lone cow at the bottom of a long field. A faint smell of treacle rising from the verges. White signposts to stows and hams and cotts – the nomenclature of another, Anglosaxon land, without the familiar Cornish tre and bos and pen that would begin just a few miles further west. A glimpse of two policemen, thumbs hitched to their shoulders, bending at the door of a shop in an empty village; then a turn into a narrower lane. 

The hedges were still higher here, and the foliage pressed in tight on either side of the car, brushing at the doors and windows. It was like edging through a silent mob. The trees swam into view again, tall and close, with the light coming through the fence of their trunks. The sky behind them was dishwater-grey. An old blue tractor, expired at the roadside with the weeds growing through the chassis; squalid barns with slurry and straw calcified in deep layers; and then I was on a lane running parallel to the A30, and the trees were standing ahead. They could certainly see me coming. 

I drove up onto a grassy bank, and stepped out. There was a gate into the bottom of the long, triangular field which the trees dominated, but I walked towards them up the lane instead. The A30 was whining noisily to the right, but this strip of tarmac carried no traffic. In the hedges: hazels showing a faint rosiness on their crenelated leaves; the port-wine colour of the hawthorn branches behind the green; and blackberries as ripe and melting as foie gras. In the distance behind, Dartmoor faded into sloe-coloured murk. 

There was something wrong with the optics of the afternoon. The light was dull, and neither I nor the hedges cast a shadow. But somehow the trees were preternaturally dark, near-black amid the flat grey-green two-tone of the afternoon. I should have taken it as a warning. 

At the top of the rise, a muddy gateway, a padlock and a faded “no entry” sign. Clearly I wasn’t the first person to have had this idea. But the trees were all of fifty feet away beyond the barrier, their great cumulus of foliage shifting darkly in the electric air. There was no one around, and these trees were our trees. They might lie in Devon, but it was we who nodded at them every time in gratitude for their signal: almost home. Surely they had the status of an embassy, a little pocket of Cornish territory islanded in an alien land. 

I awarded myself diplomatic immunity, vaulted the gate, and was across the strip of pasture in half a minute. 

It was like being in a great colonnaded hall. There were maybe 150 trees. Their trunks were slender and supremely tall, none quite true, each wavering slightly like a rocket contrail on its skyward trajectory. High above, the light came as through a vast stained-glass dome, with a susurration and the muffled clatter of wood pigeons on the move. 

From the inside, the genius of the spinney’s form was plain to see. The trees had been planted – sometime in the nineteenth century, judging by the height of them – with perfect spacing, ten or twelve feet apart, but without any grid arrangement. It gave the thing the perfection that marked it out so clearly from the road – a single compact unit that nonetheless allowed the sky to show through from the furthest side. 

The pit marked on the map lay at the eastern edge, open towards the A30 at its lower end. Approaching it from uphill, I thought for a thrilling moment that it was some kind of portal, that it led to a tunnel. But it terminated in a blind slope. 

Something about the place made me uneasy. I’d expected a sense of sanctuary, protection. Seen from the road, these were the friendliest of trees, offering encouragement for the home stretch to all passers: almost there! But this inner space felt deeply private, exclusive, and I had no share of it. It was the feeling you get when you come unexpectedly upon a site of uncomprehended ritual: burnt-out incense sticks; broken bowls; ragged votive fragments – the kind of place you walk away from with a sickly sense that you may, in your unintended trespass, have picked up an occult contagion. 

I stilled such lurid thoughts and sat down at the base of one of the trees to make some notes, but the lingering unease made it hard to concentrate. The main road was in view below, carrying a thick floodtide of caravans. But the hissing canopy overhead managed to block all but the lowest hum, like the sound of beehives on a hot day. 

I wrote a date and a first scribbled line, then stopped. There was some other mechanical noise, not from the A30, but from higher up, closer at hand: the harsh clatter of agricultural machinery. A sudden surge of alarm. I was back onto my feet and clutching at the trunk of the tree, trying to shrink behind its slender column. It wasn’t so much the “no entry” sign that had fired the panic, as that faint intimation of the uncanny within the spinney. 

The engine noise seemed to be very close, and getting closer. It sounded, in fact, as if it was right at the edge of the trees. I ducked and dipped behind the sheltering trunk, glancing wildly left and right. But the field was empty. Behind me, I could see my car through the lower gateway, five hundred yards downhill, away from the noise of the approaching, but still invisible, engine. Should I hunker down, try to hide? But the spinney was open through and through. It was a wood that offered no cover at all for a fugitive. Was that what made it an unsettling place? 

The engine was drawing closer still. Why couldn’t I see its source? Then finally a flicker of movement on the other side of the uphill hedge: the figure of a man riding some machine. I didn’t know if he had seen me, but he might as well have had a bayonet and a grey helmet. These were not my woods, and whose woods they were I did not know; I was a trespasser here in every sense. With a queasy jolt I understood that theirs had never been a friendly signal to the wayfarers below. I’d smiled doltishly at them countless times in passing without once recognizing their filigreed form for what it so obviously was: a cage. I had wandered into a trap… 

What happened next is not entirely clear, but I know that suddenly I was fleeing, a mad helter-skelter dash down the slope, pitching forward, away from the trees, in terrified expectation of something from behind – a shout, a shot, a grasping tentacle. Then I was over the lower gate and into the car, fumbling at the ignition with the metallic taste of my heartbeat high in my throat. 

In many years of wandering with blithe disregard for rights of way, confident in my ability to signal that I am, in fact, from this side of the border, that I’m alright to walk across these fields even if they’re not, I have never experienced such a moment of unhinged panic. I could make no sense of it. 

I drove on up the lane the way I had earlier walked – the quickest route back to the A30, it seemed from the map. My hands were unsteady on the wheel. I passed the higher gateway with the “no entry” sign, and then a second gateway into the next field. There was no sign of any man or any machine. 

*

It was only hours later, eighty miles to the west, lying in my bed, that it struck me. Chances are that there was someone who knew the spinney driving westward along the A30 at a particular moment on that heavy August afternoon. And as they raised their head to the left, feeling the small surge that comes with the first signal of home, they would have seen something strange, inexplicable, even uncanny: a small figure, pelting away from the trees, propelled by the unmistakable velocity of terror. Surely the unexplained image, torn past at 80 miles an hour, would have left them faintly unnerved. Perhaps they carried that unease on westwards, across the Tamar, across Bodmin Moor, past all the other signals, all the way home. Perhaps at that same moment, lying in their own bed at journey’s end, somewhere not so far away, the image was playing out again and again on the backs of their eyelids, fixing itself in their memory as a small, unquiet scar: a madly fleeing figure on a green hillside beneath the border trees. Who was he? What was he running from? And did he escape?  

It may be, then, that there are now two people who will never look at those trees in quite the same way, ever again.