In the fifth morning of his survey, Obadiah Thresher opened his field notebook to continue his calculations and found writing that was not his own, though it was in his hand. The book was bound, kept in a canvas bag, and the bag stayed under his bedroll, under his head all night. No one had touched it. No one could have touched it.

On the page after his last honest entry in ink, in his own hand, with his own way of striking the numeral seven and closing the loop of the nine, there were three additional survey lines. Angles, distances, bearings and lengths, three of them, precise as a hymn. Measurements he had never taken, for a line he had never run. He checked the ink.

It was his. He checked the hand. It was his, so exactly his that he could not have forged it himself even if he had tried. He tried, standing there comparing, holding his honest sevens against these new sevens until his eyes swam.

He thought he might have walked the line in his sleep, that some careful part of him had woken in the night, taken up the book, and worked. But a sleeper does not turn a precise angle on a brass circle in the dark without a leveled instrument, and the instrument was in its box. He was sure of it. He was almost sure of it.

It was terrifying to feel the word almost slip into the sentence where sure had been. That was the night the dreams began, if they were dreams. He would close his eyes in his bedroll and open them, and it seemed he was standing in that hollow in the dark, his instrument set up and leveled before him, his eye at the glass. He could not remember walking up to turn the angle, but there was no fear in the dream.

That was the horror of it, that it felt like nothing, like work, like the most natural thing in the world, his hands moving over the brass in the cold, the numbers coming clear and easy. He would wake suddenly in his bedroll and lie there telling himself it had been only a dream. In the morning he found dirt on his boots he had cleaned the night before. Once, only once, he woke to find his steel chain laid out full length from the camp, stretched across the grass, one end still clipped to his belt where he must have hooked it while asleep, the other end pointing like an arrow toward the hollow of the wheel.

On the gray noon of the sixth day, he did the thing he had been avoiding. He walked his curved line to its end, to the last stake he had driven, and looked beyond it, up the hollow, in the direction everything bent. Behind his newest stake, upright in grass no company had ever sent him to clear, he found other stakes. Older stakes, their iron turned red with rust, some broken at the ground, some leaning, and they were not set in a straight line.

They were curved, in the same curve. His own curved line met them exactly, as if his four good days of work had only been completing a survey someone else had begun long ago, pulled partly toward the wheel, then laid down. He traced the old stakes with his eye. The arc they made was the same arc his own stakes were beginning to make.

Same center. Same slow closing. He understood then that he was not the first to turn. He was only the latest.

In a crack in the rock beside the oldest of those stakes, wrapped in a scrap of brittle black oilcloth, he found a field notebook. It was not his. The hand that wrote it was not his. A cramped, careful, old-fashioned hand.

The ink had gone brown, and the dates at the top of the pages were from the fall of 1900. It was Cassius Vane’s book, left where Vane had left it eleven years in the weather, and somehow it had not rotted. Thresher stood in the cold morning reading another man’s survey of the same bewitched line, the same angles bending the same way toward the same center, the same growing error, page after page in that brown ink, until the last page, where the writing changed. On that last page, Vane’s old careful hand gave way in the middle of a figure to another hand, a hand that closed its letters a certain way, a hand whose strokes crossed the way Thresher’s own strokes crossed every morning when he shaved before the mirror.

The final survey in Cassius Vane’s book, finishing the line Vane never finished, was written in the hand of Obadiah Thresher himself, dated eleven years before Thresher ever set foot on that mountain. He did not turn back. His reasoning, such as it was, at five in the morning without sleep, ran like this. The trouble was worse near the wheel.

The trouble came from the wheel. Therefore the answer, whatever it was, an ore body, a crack in the rock, a spring, anything natural that could anchor any natural explanation, was at the wheel. So he would go to the wheel, measure it, understand it, and by understanding it, master it, because that was the way that had always worked. He left his corner stakes standing.

He took only his instrument, its tripod, his chain, his book, and his lamp. In the gray light before dawn he walked up the dry creek bed toward the mill. As he climbed, the quiet that had accompanied him since the first day grew thicker. He noticed he could no longer hear his own footsteps on the stones of the bed.

He stamped hard on a flat rock and heard nothing. Not a rustle, though he felt the jolt through his heel, and there is a particular cold that runs up a man’s spine when his foot is that close to his own ear. Fog rose off the ground as he climbed, not down from the hillside as real fog does, but out of the dry creek bed itself, out of the stones. A pale fog that gathered on his beard and had no taste.

No damp. No earth. Nothing. It thickened until his lamp was a faint yellow blot an arm’s length from his face and the world around him was gone.

A careful man would stop, but he was holding his chain, and a chain is a rope, and a rope, if you hold it, will lead you home. So he kept climbing, hand over hand, up his own chain stretched toward the mill. Then the sounds began, if sounds they were. Under the stillness of the night there was a faint working noise, a grinding, the sound of a millstone turning on grain falling into it out of the fog, patient and regular, the sound of a mill working hard in a mill that had not worked in a hundred years.

Under the grinding, so faint he told himself it was only the pulse in his ears, a voice reading. He could not make out the words, only their rise and fall, like a man reading figures from a page, a rhythm he had repeated thousands of times over his own field books. With every few feet of climbing the voice grew a little clearer and the rhythm more familiar, until he forced himself to stop listening so closely, because he was beginning to suspect whose voice it was, and he was not ready to be sure. The mill came out of the fog suddenly, ahead of him.

What he found was plain enough. The old gristmill, tilted and gray, its roof collapsed long ago, its stones black with a century of damp. And the wheel. The great wooden wheel stood against the side of the mill over a dry race, over stones where no water had run for a very long time.

It was turning. Slowly, steadily, groaning on an axle that should have rusted and rotted and fallen to the ground two generations past, it turned as if a full stream poured over it in a race that was perfectly dry, in an absolute stillness without wind. It turned as a thing turns that has been turning for a long time and intends to keep turning a while longer. Thresher stood before it, and the surveyor’s instinct, the calculation, the creed, took hold of his fear, because it was the only prayer he knew.

He would measure the wheel. He set his tripod on the stones. He leveled his instrument with hands that were not quite steady. He sighted the hub of the turning wheel, reached out to turn his angle, and read it off the brass.

The wheel stopped. Instantly, without slowing, the way something stops that was not really moving at all, that was only being shown to you. It stopped. In that vast new silence from the dark heart of the mill, a voice began to read.

It read numbers, angles, distances, bearing and length, bearing and length, patient and slow, in a voice he knew better than any voice in the world. It was his own. The voice of Obadiah Thresher himself came out of the dark of the mill, reading a survey. And he realized, standing there with his hand still on the brass circle he had not yet turned, that the numbers the voice was reading were the numbers he was about to read.

It was reading them before he could read them aloud. It already had them. It had had them, he understood, for a very long time. He tried to stop.

That is the thing to hold onto, the most human thing in the whole account. He lifted his hand from the brass circle. He told himself he would not read the next angle, would not turn it, would break the rhythm, deny the voice the one thing it seemed to want, which was to read the line. His hand returned to the circle by itself.

He watched it move. He watched his fine ink-stained fingers settle on the brass and turn the angle, smoothly, expertly, calmly, and his mouth opened and his own voice read the number aloud, half a breath behind the voice in the mill, so that the two of them, one in the dark and one on the stones, read the same number together in the same voice, the way two men sing a hymn they have known since childhood. Then came the worst thing, the thing that broke the calculation in him for good. He realized he could no longer remember reaching the mill.

He could not remember the climb, or the fog, or the chain in his hand. He could not remember the four good days of work, or Alton Crowe behind his desk, or the wagon, or even the door of his own house far down the mountain. He reached for his history the way a man reaches for a drawer in the dark, sure of where it is, and his hand found nothing. He could remember only the numbers, the bearings and the lengths, as if somewhere during the reading, in his own patient familiar voice, he had been surveyed and measured, converted, angle by angle, into a line, and entered into a book in a hand that resembled his, on a mountain that kept what it measured.

He said one thing then, and the record preserves it because he wrote it himself eleven days later, the only thing he ever wrote about that morning, in a shaking hand at the bottom of a county statement, and after that he never spoke of it to any living soul. He said, “It is not I who holds the chain. ”

He walked back down the dry creek bed, past the last farm where no lamp burned and no old woman sat, down to the lonely road, then to the fuller road, then to the wagon, and he did not look back once, afraid that if he counted his steps he would find the number written somewhere waiting on his palm. The trip should have taken a day, or less.

By his own careful calculation it took six hours from the wheel to the wagon, and he remembered none of them. He remembered only the moment of coming back to himself on the road, and later, after a long while, his hand pressing the cold iron brake of the wagon in a gray dawn. Between those two moments there was nothing at all. No fatigue, no hunger, no deep ache in the legs after a hard descent, only a smooth emptiness where the time should have been, as if those hours had been lifted out of him entirely and put somewhere else.

When he finally searched the pockets of his coat he found a short worn pencil and eleven small stones, round river stones, which he did not remember gathering, set in his pocket in careful order, each stone spaced a short distance from the next, the way survey stakes are spaced. He took them out and looked at them a long time in the growing light, then put them back, because for reasons he could not explain he could not bring himself to throw them into the ditch. He came down off that mountain nine days after he went up, though by his own account he had spent only one morning behind the wheel. Nine days.

He could not account for eight of them, and he did not try. The company sent a man halfway up on the sixth day, worried by the long silence, and that man came back pale and quick and would not go up again for any wage. He reported that he could not find the surveyor’s camp at all, that where the camp should have been there was only bare grass and a cold fire ring that looked as if it had been abandoned for years, moss grown over its stones. And he said that from the bottom of the hollow he heard a regular grinding, and under it, a man’s voice reading numbers quietly, without hurry, and that he, being a reasonable man with a family, had chosen not to walk toward it.

So they were not entirely surprised when Thresher came out on the ninth day. They were only surprised that he came out at all. He reached the depot town pale as sea ash and thin as an iron rod. His instruments, the transit and tripod and steel chain and every iron stake, all the tools of his working life, lay abandoned in the fog.

Everything except the field notebook, which he carried inside his coat, pressed against his chest, and would not let any living creature touch. When Alton Crowe came out from behind his desk, heavy with questions about the map, the corners, the sixty days, Thresher put his ink-stained hand on the desk to steady himself and said only that the land could not be traversed. Crowe pressed. There was money in it, attorneys waiting, and Crowe had never climbed the mountain and did not believe in mountains that could not be traversed.

He asked what, exactly, had stopped a man in his thirtieth year of work. Thresher looked at him a long moment, then lied, because the truth was not speakable in the words of a man behind a desk. He said the terrain was rugged. He said the ground would not hold an angle.

And Crowe, who wanted a reason he could enter in a ledger and be done with, accepted the reason gladly. It is still entered in the county records to this day. Survey abandoned. Terrain rugged.

Two neat words for something that was neither. Cassius Vane, the surveyor who went up in 1900 and simply left the county, was never found, and no one searched for him with any seriousness. Vane also left his instruments on that mountain, and when Thresher abandoned his own transit at the wheel, there was already another instrument standing in the fog, old, rusted, on a rotted tripod, leveled and calibrated on the same hub. Thresher never mentioned this to Crowe.

He mentioned it only once, in a single line of his statement, and then never again. As for Zelpha Renn, when a man from the company climbed up weeks later for a clearer account than Thresher’s, he found the last farm on the mountain long empty. The porch was sagging, the roof open to the weather, the cookstove cold and rusted with winter, and no sign that any living person had sat shelling nothing into an empty bowl on that porch in twenty years or more. He asked about her in the depot town.

Erastus Grimshaw told him the Renns had once lived on that road, and among them a woman named Zelpha, and that she had been buried before the turn of the century. She had died at least twelve years before Thresher climbed up to listen to her. When they told Thresher this, he showed no surprise and offered no explanation. He asked only one question, quietly, whether the bowl was still on the porch.

They told him there had never been a bowl. He nodded slowly, as if that were an answer he could keep, and went back to his copying and his glances over his shoulder, and said nothing about it then or later. No survey of Cold Glen Hollow was ever completed. The company let the land go for back taxes rather than send another man, and it returned to the blank space on the map where the printers had run out of names, and so far as anyone knows, it remains there.

Obadiah Thresher lived thirty-one more years. He never ran a line again. He worked as a clerk copying numbers other men had measured, and he was good at it. He did his writing with his back to the wall, so that nothing stood behind him while he worked.

He kept no compass in the house. He would not own one, would not touch one, and when a young clerk once set a small brass pocket compass on the desk beside him, meaning nothing by it, merely emptying his pockets, Thresher rose without a word, put on his coat, left the office, and did not return until the next morning. The compass had been quietly put away by then and was never used again. He never ran a line of his own after Cold Glen, never changed direction his whole life.

He would not even look down a fence to tell you whether it was straight. In the one moment, late in his life, when anyone was able to draw out of him anything at all about the matter, he said that a man should be careful what he sets out to measure, because measuring is a kind of asking, and there are things in the high hollows that wait a very long time to be asked. Every man who worked beside him in those years noticed the same small thing, that Thresher could not write a number, a page number, a sum, not even the date at the top of a letter, without glancing quickly over his right shoulder at the empty room behind him, as if checking that the hand writing this time was his own. He kept his old field notebook, the one he carried down from the mountain, until the end of his life, and after his death it passed to the county with his other papers.

A clerk cataloguing the map noted, in a dry official hand, that its final pages were filled with a completed survey, a closed traverse, running corner to corner, with the length and bearing of every leg, meeting at its starting point, a perfect line enclosing a tract of land in Mercer County that Obadiah Thresher had sworn under oath he never finished, never closed, and had deliberately left open in the fog. The clerk noted that the date was eleven years after his death. In 1951, forty years after the survey was abandoned, a timber estimator walked into that blank part of the map, knowing nothing of the story, looking only for marketable pine. He came out fast and gave few statements.

He told the men who sent him that he had lost most of the day up there without being able to explain it properly. That the fog had come up out of the dry ground instead of down off the hills. That for a while he had heard what he first took to be a working mill nearby, a grinding, and a faint voice running beneath it, reading something aloud, until he forced himself to stop trying to hear it. But he said one thing that was written down.

At the ruins of the old mill, in a race that was perfectly dry, he found a ring of iron stakes standing in the grass. Old stakes, rusted almost through, and newer ones, and newer again, driven at different times by different hands over the long years. And every one of them set in a perfect curve, an arc that went on and on until it closed. A circle of stakes around the mill and its wheel.

Thirty-one stakes on the near side alone, where he counted before he stopped counting. He said he did not finish the count. He said that halfway around the ring he began to feel that the counting itself was the danger, that tallying the stakes was finishing the work the ground had been waiting for, adding his sum to a total that had been accumulating on that mountain longer than the state itself had existed. And at the moment that feeling took him, he put his notebook in his pocket and walked out, and did not stop walking until he was well clear of that blank spot on the map.

At the center of the circle, the wheel stood over the dry race, not turning. He was very clear about that. It was not turning.

It looked, and he never forgot his choice of the word, like something that had stopped for the moment, waiting with a patience beyond any limit for a reason to begin again.