The end came on a Thursday, eleven days after Ransom Coldiron arrived at the camp above Cuddel Gap. He had stopped sleeping well by then. Twice he had caught himself standing motionless in the main entry, lamp in hand, tapping the handle against his thigh in a rhythm he had not chosen: three taps, a pause, three taps. He had to force himself to stop, and the effort frightened him more than the tapping itself.

He went to Captain Orean Threadgill and told him everything. The surveys that would not agree. The chain that gave him a different mountain every time he ran it. The compass on the slope.

The four names in the desertion book. And Threadgill, who had sworn on the first day that he was not a frightened man, put his scarred hands flat on the table to keep them still and told Coldiron the truth he had been holding back. He had gone into the low cut himself, once, early on, after the first man disappeared, because a captain does not send his men where he will not go himself. He had walked about forty feet past the old face, past the hundred-and-forty mark, into the part of the mine that was not supposed to exist.

His lamp had sunk to that low blue bead. The knocking had begun, slowly. And he had done the one thing old Crockett Scaggs warned against: he had counted. He heard the knock and his mind supplied the number without his meaning to, and when the next knock came his mind supplied the next number.

The terrible part was not the fear. The terrible part was the good feeling, a relief, like being called in from a cold field to a warm supper, something warm wanting him, and he had taken four steps toward the wall before the harder part of him realized his feet were moving and his hand had already dropped the lamp. He turned and ran, fell and ran, and came out of that mine on his hands and knees into daylight, and had not passed the last crosscut since. What stayed with him was not the pull.

When he turned and fled, the knocking did not quicken or anger as something that wants you would. It softened. It grew patient. That patience was what nearly undid him, because the thing did not need to chase him.

It had already decided it had all the time there was, and he was only a man, and men come back. Men always come back. Now you are here, Threadgill said. You are the company.

Tell me what we do, because I cannot take any more of it. What they decided to do was what closed the mine, and it should have ended the matter but it did not. Coldiron made his decision as an engineer. He would get the truth by measurement, one last precise measurement, and then he would have grounds to close the mine on paper that the company would accept.

He would enter the low cut one final time and face it, wherever it was that day, properly surveyed, with another man holding the far end of the chain, with a line of safety lamps spaced at regular intervals so there was always light between him and the mouth of the cut. He would put cotton in his ears so he could not hear the knocking and be caught counting. It was a sound plan. It was the plan of a man who still believed the thing could be beaten methodically.

Threadgill did not go. Coldiron did not blame him and did not ask twice. The man who went in with him, holding the far end of the chain, was Crockett Scaggs, the old timberman who had refused the low cut for a year. When Coldiron asked him why he would go now, after everything he had said, Scaggs told him that Coldiron did not have the good sense to be afraid in the right way, and a man like that should not go down alone.

Besides, he was sixty-six, and his lungs were failing, and he would sooner have the mountain carry him out on its feet than lie in that camp and lose his breath by degrees. They moved out before dawn, both of them stopped up with cotton, carrying a good chain and a lamp apiece and four safety lamps to set along the way. They walked the main entry down its straight, sound length to the last crosscut and past it, into the low cut, in the part of the mountain whose measurements changed every day. Coldiron set the first safety lamp at the crosscut.

They ran the chain out to the old face, the hundred-and-forty mark, where ten years of maps said solid rock should be. The entry continued. He set the second lamp there. The cotton in his ears was useless against something that was not truly sound, that slow patient knocking he now felt in his teeth and in the long bones of his arms more than he heard it.

After the old face, the walls of the entry were wrong. Not cut, not the clean flat ribs of a driven entry. Smooth, he wrote later. Slick, and curved like the inside of a throat.

The coal was no longer coal but something darker that reflected no lamp light at all, that drank light instead of giving it back, until the small blue flames seemed to light nothing but themselves. The air past the old face was not cold as a mine is cold. It was cold as the hollow under a lifted stone, a wet, smothering cold, and it moved against his face, coming out of the dark ahead of him, which was backwards, because the air in an entry should draw in toward the workings, not out of them. He stood a moment feeling the mountain breathe on him, and understood with his whole body what his instruments had been trying to tell his mind for a week.

He lit the third lamp. The chain read one hundred and eighty feet and he kept counting. The floor began to slope gently downward, the way a thing slopes to help you along, and the walls came in until he could touch them both at once, and still he kept counting. And Scaggs, behind him, had stopped counting and stood holding the chain in both hands with his mouth moving in words that were not quite words, and Coldiron suddenly understood that the old man, the one man in the county who knew better than anyone, had let it take him, and was counting there at the end.

With his ears stopped, it had reached past everything and found him, found the one pulse a dying man cannot stop cotton against, the slow beat of his own heart. The survey is in the record. Its last line, in Coldiron’s broken hand, marks a distance of two hundred and twenty feet, then a number he began and did not finish, as though the pen had been snatched out of his mind. He set the fourth and final safety lamp a little past the third, because it was found there later with its oil burned out.

He and Scaggs came out of that mine, which not everyone in this story could say, and they came out running, and the chain was left behind, run out full length into the dark. No one went back for it. Scaggs never said what drove them out. He only said that Coldiron had gone ahead of him in the dark where the floor sloped and the walls closed in, and stopped, and stood still at the edge of the last lamp light, with his back to Scaggs, unmoving and silent for so long that Scaggs understood the engineer was gone as the foreman had gone, taken, keeping its rhythm.

And Scaggs did the one thing he had spent his whole life in that mountain learning never to do. He stepped forward into the dark toward the thing and took hold of Coldiron’s coat with his old hands. He did not pull. You cannot pull a man back from it, he said.

Pulling only makes him hold on harder. What he did was put his mouth to the engineer’s ear and speak the name of the man’s wife, the one name he had heard once at supper, the one pulse of the outer world the mountain had not yet learned. And Coldiron came back to his eyes suddenly, like a man surfacing from deep water. Then they ran.

What Coldiron saw in that place he refused to write down, not in the survey and not in the letter. The one time he was asked face to face, years later, by a man who had traced the story to him, Coldiron went still and said only that he had been waiting, that the thing had known his name before he gave it, and that the worst of it was not that it meant to hurt him. The worst of it, he said, was that it was so patient and so glad and so much older than hurting. They closed Number Three within the week.

Coldiron wrote the order himself, the superintendent signed it, and the company accepted it because Coldiron was smart enough to give them a reason they could enter in the register and defend to the owners. The reason he gave them, the two words that remain in the company records to this day as the cause for closing a mine sitting on the best coal seam in the county, were air contamination. Two words, a lie signed by a frightened man so he could leave the mountain and not give it one more hour of his life. They bricked up the entry, poured concrete over the brick, and set a date stone in it: 1922.

Coldiron stood and watched them do it and made them do more than the company wanted. He made them come back three times for more brick and more concrete, and build a wall as thick as a bank vault. The masons grumbled, and the superintendent asked him what he thought was going to come out of an exhausted hole. Coldiron did not answer.

In the letter, the one he asked his wife to burn and she did not, he wrote what unsettles me when I let it. He wrote that while they were laying the final brick, with the wet mortar still soft, from inside the sealed mine, from behind the new wall, after they had made sure every man was out and standing in the daylight, something knocked. A slow, patient knocking, and it was not three and it was not four. He counted it, he wrote.

He could not stop himself. He counted, and the number was the exact number of men who had gone into that mountain over the years and not come out, counting backwards. He was sure of it. Past the boundary, to Quarles, and before Quarles.

It counted them all out, slow and long, and then it knocked once more, one extra knock, slow, and he understood that the last one was for him, a place saved, a seat reserved. Sealing the mountain had not stopped it. It had only asked him to wait, and the one thing he had learned about that mountain was that waiting was the thing it did best. Elihu Quarles, the silver man of the 1870s, left the county and was never traced again except as a name on a single passenger list leaving a Gulf port, with no return.

Threadgill, the captain, lived nineteen more years and never went underground again for any reason. He worked above ground as a guard and a guide, and died in his bed, which in this trade counts as a kind of victory. But his family said he slept with a lamp burning every night of those nineteen years, and could not bear closed doors, and near the end, when his mind wandered as old men’s minds wander, he would sometimes stop what he was doing and tilt his head and listen, and count under his breath, and need to be spoken to twice before he came back. Crockett Scaggs, the old timberman, who went down against every reason he had to save a stranger from that place, outlived his failing lungs by a decade, which the doctors could not explain.

He said until his dying day that he did not know why it had let the two of them out while it kept better men, unless it had wanted the story told so that others would come, and that the patient thing had no need of hurry and knew it. Ransom Coldiron, who believed in nothing much and believed in numbers, resigned from the company and left engineering for good. He never surveyed another foot of ground in his life, and spent the rest of his long, quiet years as far from any mountain as he could manage, on flat, open land where you can see the weather coming from every direction. He told his wife, who wrote it in the margin of the letter she did not burn, that he had moved them there for one reason only.

On flat land nothing is above you and nothing is below you and nothing can knock at you. She wrote something else in that margin, in different ink, as though she had added it years later. She wrote that he was a good husband and a quiet man, and that she saw the old fear come back to him only once, long after, on a still night when the hall clock stopped running and the house fell silent in the usual way. And in that silence, something somewhere in the walls or the pipes or the settling of the old house knocked, very slowly.

Her husband sat bolt upright from his chair and would not let her wind the clock that night, and stayed awake in the dark until dawn with his hands pressed over his ears, like a man holding his head. The seal is still there if you want to go and look for it, and I ask you not to. The company is long gone. Of the camp only a few cellar holes and a chimney remain in the laurel, and the slate pile still glows under the ash as such piles do, enduring the way the other things in that gap endure.

The date stone is still legible, as I am told: 1922, cut deep into the concrete. People go up there, not knowing what they are standing in front of, and put their hands on that cold wall as one does with old things. A few of them, not many, say that when they took their hands away and turned to leave, from somewhere behind the brick and the concrete, from a mountain of sixteen feet — which is in truth closer to two hundred — they heard a knocking. And every one of them, every single one, says the same foolish thing, the thing Crockett Scaggs begged a frightened engineer never to do a century ago in the dark.

They say, I counted. One man, who went up a few years ago with a camera and more nerve than sense, left a recording of the sound hitting the wall all night, and said afterward he could not make himself listen to it all the way through. The first hours were nothing, just drip and wind, and then in a small part of the night the dripping stopped suddenly, the way a thing stops when something listens back at it. And after the dripping, there came a slow, regular, spaced sound, and he turned off the recording and threw it in the creek, and refused to say the number, but he said one thing, and I will leave you with the hardest part of this.

He said it was not knocking to be let out. It was counting.