The corrosion appeared in the third week of June, and Edward Ashworth was the first to document it. He was a records clerk in the municipal office of Meridian Falls, a small town in the upper reaches of the state where the mill had closed twenty years ago and the river had learned to run clean again. The pump house on Foundry Street was a squat brick building from 1911, and the registers stood in a row in its lower vault, each the height of a tall man, their brass casings the color of old pennies. The third register from the left had begun to weep a pale green salt along the seam of its bell housing, crusting on the lower plate like a shoreline at low tide. Edward photographed it from three angles, noted the oxidation in the standardized language of the district assessment manual, and entered a mild anomaly on the condition statement. He had done this kind of work for eleven years and he knew the vocabulary of decay: spalling, fatigue fracture, galvanic action, fretting. But the weeping of the third register was not any of those things, and when he put the back of his hand against the casing, the brass was warm.

He had grown up in Meridian Falls, had walked past the pump house all his life, and had never given the registers more than a passing thought. They were relics, he believed, charming and obsolete, their dials and drums disconnected from any function that served the town now. His duties were routine: inventory, condition report, recommendation for disposal. He lived alone in a rented room above the old hardware store, ate his meals at the diner on Main Street, and kept a small ledger of his own expenditures, which he balanced to the penny every Sunday. He was not an unhappy man. He was simply a man who had arranged his life around the absence of incident, and the warmth of the third register was an incident. When he returned to the office that afternoon, he filed his report and then sat for a long time at his desk, staring at the photograph of the weeping seam, feeling in his chest a low and unfamiliar vibration, like the echo of a struck bell in a distant field.

Margaret Holloway came down from the regional headquarters in the second week of July. She was a compact woman with steel-gray hair and an aluminum clipboard, and she walked through the pump house with the restless efficiency of a person who had already made her decision. The registers, she explained, represented an unsustainable maintenance liability. The district had approved their decommissioning, and the contractors would arrive in the autumn. She asked Edward whether the equipment could be safely bled of its residual pressure, and he replied, carefully, that he did not know what the pressure was, or where it came from. She smiled in a way that suggested he had misunderstood the purpose of the question. She instructed him to prepare an inventory for the disposal auction, and to have the vault ready for the contractors by the first of September.

The town began to change during the weeks that followed, though at first Edward could not say how. People forgot appointments. The barber on Main Street began calling his own son by his brother's name. A woman at the library asked where she lived, and then laughed, and said she was tired, that was all. The light in the afternoons acquired a peculiar dimness, as though a cloud had passed over the sun, but when Edward looked up, the sky was clear. The river, which ran beneath the pump house, seemed to be running more slowly, and the water carried a faint metallic smell that none of the old men by the bridge could remember. Edward walked down to the vault one evening without intending to, and found the third register humming — a low, sorrowful note, like the inside of a shell held to the ear, but broader, deeper, and somehow full of weather.

It was Thomas Bradshaw who told him the truth. The old engineer appeared in the records room on a Friday afternoon, wearing a black wool vest despite the heat, and introduced himself without ceremony. He had designed the registers, he said, sixty years ago, when the town had asked him to solve a problem that no one had been able to name. The problem was this: Meridian Falls had too much memory. Every town accumulates the excess of its lived time — the grief of widows, the restlessness of young men, the quarrels and reconciliations, the long winters — and when that surplus grew beyond tolerance, the people began to drown in it. They forgot themselves, or they remembered too much, or they left. Bradshaw had built the registers to hold that surplus, to absorb the accumulated time of the community and store it in a resonance that the town could draw on without being overwhelmed. At the core of the mechanism was a single reference note, a carrier frequency, tuned to a summer in 1891 when the dam was raised and the town had cohered around a common purpose. That summer was stored in the registers, kept warm, kept alive, so that Meridian Falls would always know itself in the key of its best season.

Edward listened in silence. He wanted to believe it was an old man's delusion, but the warmth of the third register was still on his hand, and the hum of the vault was in his bones. Bradshaw then told him the cost. A resonance vessel of that kind could not be left unattended. It required a substrate, a living body coupled to the intake, someone whose own life could be drawn through slowly, like tinder feeding a flame, to keep the carrier note from cooling. Bradshaw had been that substrate for forty years. He had married a woman he loved, and he had fed his years with her into the machinery — the ordinary mornings, the arguments, the smell of her hair at night — until there was nothing left of his marriage but the hollow impression of it in the archive of the town. He had raised a son, and fed the son's growing weight into the vault, and the son had gone away without knowing why his father was so old. He showed Edward his hands: the skin gone thin as paper, the fingers worn at the joints like old tools, the veins faint as pencil lines. The registers had taken almost everything. Bradshaw said he did not regret it, but he was finished, and the mechanism was failing, and the town, which had poured its memory into the vessels for a century, was about to receive it all back at once.

The crisis came in August, when Margaret Holloway advanced the decommissioning date. The contractors were on site, and Edward watched from the pump house doorway as they opened the bleeder valves on the lower manifold to relieve the internal pressure before the equipment was cut free. The sound that came out of the vault was not a hiss of gas but a low, oceanic groan, and the town heard it — every person in Meridian Falls stopped where they stood, in the street, in their kitchens, at their desks, and for a moment no one could remember their own name. The light failed at noon, the river ran backward for a span of a hundred heartbeats, and when Edward reached the vault, Bradshaw was already there, his hand clamped on the intake valve, his face the color of tallow, the veins of his neck standing out like cords. The old engineer was trying to take the load into himself, to dam the returning flood with the last of his ruined body. Edward saw the register's dial spin and spin, and Bradshaw's lips moving, but there was no sound, and then the old man fell, his hand still on the valve, his eyes open to the ceiling, and the groan of the vessel rose and rose.

Edward did not think. That was what he understood later, when he tried to give an account of it: there had been no thought, no deliberation, only a movement as natural as the turn of a key in a lock. He lifted the old man's hand from the intake and knelt in the space that it had occupied. He remembered the summer of 1891, although he had not been born — the smell of the pine tar, the sound of the bell hanging from the new dam, the heat of the sun on the shoulders of the men who had come to raise the town into coherence. He remembered it because the registers held it, and the registers were pouring it out, and he opened himself to receive the flood. The mechanism took hold of him not as a machine takes hold of a body but as a body takes hold of its own weight. He felt the intake manifold draw on the years of his life, on the small rooms he had lived in, on his bills and his ledgers and his loneliness, on everything he had ever counted and everything he had never dared to count. The distant summer passed through his chest, through his sinuses, through the bright strands of his own memory, and he gave himself to it. He gave his name, his age, his habits, the face of his mother, the sound of rain on the hardware store roof. He gave the town to the town, and the flood found its channel, and the hum of the registers quieted to a hum at the edge of hearing.

September came. The contractors, after a search, pronounced the vault unstable and recommended that the shaft be sealed with concrete rather than dismantled, and Margaret Holloway, who had no reason to believe otherwise, approved the measure. The registers were entombed under Foundry Street, where they continued, at a frequency no instrument could detect, to hold the excess of the town's life. Meridian Falls regained itself. The barber remembered his son. The woman at the library found her way home. The light in the afternoons returned to its ordinary quality, and the river ran at its ordinary speed, and the town held its autumn festival as it had always held it, with apples and cider and the bell of the dam ringing across the water.

Edward Ashworth was found on the floor of the pump house with his left hand resting on the manifold of the third register, and because he could not speak his name or any detail of his former existence, he was taken to the county care home, where he was given a small room that overlooked the garden. He sat there through the turning of the leaves. The nurses found him a gentle and undemanding patient, a man who smiled at the light, who ate what was placed before him, who watched the birds without curiosity. In his chest, faintly, a note still sounded, and he could feel, at the base of his skull, a pressure like a bottle being carried upward through still water. It was the last of the distant summer, passing through him on its way back to the town that had been given to itself by his consent. He did not know the town's name. He did not know his own. He knew only that somewhere there was a wholeness that he had served, and that it was enough, and he let the pressure rise, and he let it go, and the room was full of the pale low light of that far and completed season, and he was not sorry.