The resistivity meter arrived in a cardboard box lined with bubble wrap that still smelled of the warehouse in Pittsburgh where it had sat on a shelf for seven years. It was a Geophysical Survey Systems Model 4100, manufactured in 1998, and when Danny Miller plugged it in for the first time in the back room of his mother's gas station, the display flickered twice before settling into a steady green glow that illuminated the dust on his hands. The manual was missing, but the controls were simple enough: a dial for sensitivity, a toggle for depth range, a series of ports for the electrode array. Danny had spent two hundred and eighty dollars on the unit and ninety more on the electrodes, and when he carried the equipment out to the abandoned parking lot north of the station on that first afternoon, the weight of the case in his hand felt like the weight of something that might finally give him an answer.

There are two ways to tell what happened next. Both are coherent. Both are supported by the available evidence. The problem is that the evidence will not resolve itself into a single version of the truth, and Danny — who is the only person who could collapse the wave function by choosing which version to believe — has never been able to decide.

Version A is this: the cavities were real. The ground beneath Youngstown was a honeycomb of abandoned coal mine galleries, some of them dating back to the 1870s, when the first shafts were sunk into the Pittsburgh coal seam and the first loads of bituminous were hauled up by mule and cable. The mines had been sealed on paper in the 1960s, but the sealing consisted of little more than wooden bulkheads and a few feet of packed earth, and over the decades the bulkheads had rotted and the earth had settled and the galleries had become exactly what they had always been destined to become: voids. Empty spaces. Holes in the earth that had been waiting for sixty years to collapse. Bill Miller, Danny's uncle, had discovered this before anyone else. He had been a geological engineer at the Maple Creek Number Four mine, and in the three years before his death he had mapped the entire subsurface of the city with professional-grade ground-penetrating radar and seismic tomography equipment. His notebooks documented cavities ranging from ten feet to eighty feet in diameter, expanding at rates that accelerated year over year. He had written to the Ohio Department of Natural Resources, to the Mine Safety and Health Administration, to the Youngstown city council. He had been ignored. He had been told that his data was "alarmist" and his conclusions "speculative." He had taken his findings to Mayor Henderson, who had been mine safety supervisor at Maple Creek Number Four before entering politics, and Henderson had stopped returning his calls. Three weeks later, Bill was dead in a cave-in at the very mine where Henderson had once been the safety supervisor. The official report called it an accident. Danny's Aunt Carol, who had left for Florida immediately after the funeral and never spoken of Youngstown again, called it something else, though she would never say what.

In Version A, the man in the suit — Leland, the one who paid Danny three hundred dollars to take resistivity readings at specific coordinates — was not a random geological survey contractor. He was an investigator. He had been sent by someone, or had sent himself, to confirm what Bill had found, and when he gave Danny that list of equipment and those coordinates, he was not hiring a gas station attendant to do odd jobs. He was recruiting an heir. He was passing the torch to the one person in Youngstown who had both the motivation and the access to continue the work that Bill had started.

In Version A, Danny's resistivity readings matched Bill's notebooks exactly. The cavity under the high school gymnasium, the one with the 1978 state basketball championship banner, measured seventy-eight feet in diameter — two feet wider than Bill's last measurement, confirming the expansion rate that Bill had warned about. The cavity under Kenmore Avenue, where Gus Pappas's house would eventually fall, measured thirty-four feet across and was connected by a lateral gallery to the larger void beneath the Sheet and Tube works, creating a structural weakness that any competent geologist would recognize as a precursor to catastrophic collapse. Danny took his data to the mayor and was dismissed. He took it to the Tribune and was told it was unverifiable. He took it to his mother, and Sally read Bill's notebooks and wept and said she had known all along, in some way, that the ground was not solid beneath them.

In Version A, the house collapsed on a Tuesday morning in October because it was sitting over a hole that had been expanding for sixty years and had finally reached the point where the overburden could no longer support the weight of a two-story colonial with aluminum siding. The mayor called it an isolated incident, and Danny watched the press conference on the gas station television and understood that he was living inside the same story that had killed his uncle: discovery, warning, denial, collapse. The recursion was perfect.

Now consider Version B.

In Version B, Danny Miller was a twenty-four-year-old man who had not slept more than four hours a night in the three years since his uncle's funeral. He had been close to Bill in a way that he had never been close to his own father, who had left when Danny was seven and had not been heard from since. Bill had taught him to drive. Bill had taken him fishing on the Mahoning River. Bill had shown him how to read a topographic map and how to identify the different grades of steel by the sparks they threw off a grinding wheel. When Bill died, something in Danny had collapsed inward, like a gallery roof giving way, and the space that Bill had occupied in Danny's life had become a void that Danny had been trying to fill ever since.

In Version B, the man in the suit was exactly what he appeared to be: a low-level contractor for a geological survey company that was mapping abandoned mine workings for a federal infrastructure assessment. There was nothing unusual about his approach, nothing conspiratorial about his payment, nothing significant about the coordinates he provided. He had stopped at the gas station because it was the only open business on that stretch of Mahoning Avenue, and he had offered Danny the job because Danny was young and looked capable and was standing behind the counter with nothing to do.

In Version B, the resistivity meter was a piece of surplus equipment that had been sitting in a Pittsburgh warehouse for seven years for a reason: it was unreliable. Its calibration drifted. Its depth readings were approximate at best. Its electrode array was missing two leads, which Danny had replaced with speaker wire from RadioShack, and the impedance mismatch introduced errors that Danny did not know how to correct because he had never been trained in geophysical survey techniques. The cavities he detected were real in the sense that abandoned mine workings existed beneath the city — everyone knew that — but his measurements of their size and expansion rate were artifacts of faulty equipment and confirmation bias. He was not measuring the ground. He was measuring his grief, projected downward through a broken instrument into the darkness beneath the city.

In Version B, Bill's notebooks were the product of a man who had been under extraordinary stress in the final years of his life. Bill had lost his job at the mine consolidation company six months before his death, laid off in a round of cuts that eliminated the entire geological engineering department. He had been drinking heavily. He had been taking prescription sleep medication that his doctor later admitted had been prescribed at too high a dose. The notebooks were real, and the measurements in them were careful, but the conclusions Bill drew from them — the accelerating expansion rate, the imminent collapse, the conspiracy of silence — were the product of a mind that had been unraveling under the combined pressure of unemployment, isolation, and pharmaceutical side effects. The cave-in that killed him was an accident, as the official report said. Bill had entered a sealed gallery alone, against protocol, because he was not thinking clearly. The roof had been unstable for years. Everyone at the mine knew it.

In Version B, the house on Kenmore Avenue collapsed because of a water main break that had been slowly eroding the soil beneath the foundation for more than a decade. The mine gallery exposed at the bottom of the hole was unrelated to the collapse — it was simply there, a preexisting void that the house had happened to fall into. The city's water infrastructure was old and poorly maintained, a victim of the same budget cuts that had eliminated Bill's department, and Gus Pappas's house was not the first structure in Youngstown to be undermined by leaking pipes. It would not be the last. But it was not evidence of systemic geological collapse. It was evidence of municipal neglect, which was a different kind of tragedy entirely.

Both versions are logically coherent. Both explain the available evidence. Both account for Bill's notebooks, Danny's readings, the house on Kenmore, the mayor's dismissal, the silence of the town. In Version A, Danny is a man who has inherited a terrible truth and tried to act on it, only to be silenced by the same forces that killed his uncle. In Version B, Danny is a man whose grief has become a kind of madness, a closed loop of measurement and confirmation that feeds on itself and cannot be broken by external evidence because external evidence is filtered through the same damaged equipment and the same damaged mind.

The two versions coexisted in Danny's head for the entire autumn of that year, superimposed like two radio signals on the same frequency, neither strong enough to drown out the other. When he looked at the resistivity data on the green screen of the Model 4100, he saw both the objective record of a collapsing subsurface and the fever chart of his own unprocessed grief. He could not tell which was which. He could not tell whether the instrument was measuring the ground or measuring him.

The collapse came on a night in late November, when Danny sat in Bill's study for the last time, the three black notebooks spread on the desk before him. He had been reading Bill's final entry — the one with the revised expansion rate and the margin note about Henderson — and he had been trying to decide whether the handwriting at the end looked like the writing of a man who was seeing something clearly or the writing of a man who was losing his grip. He could not decide. The evidence would not resolve.

He closed the notebooks and stacked them neatly and left them on the desk. He went to Tommy's apartment above the closed laundromat and found his cousin on the mattress, the portable television flickering silently, and said: "We're leaving." Tommy asked where. Danny said west. Tommy said okay.

They drove out of Youngstown on 422, the truck's headlights cutting a narrow tunnel through the darkness. Tommy fell asleep. Danny drove. The land flattened out. The road unwound. And somewhere past the Indiana line, as the sky began to lighten in the rearview mirror, Danny made the choice that collapsed the wave function. He did not decide that Version A was true or that Version B was true. He decided that it did not matter. Both versions led to the same destination — the gas station behind him, the town behind him, the void behind him, whatever its cause. The truck was moving forward. The road was solid beneath the tires. That was the only measurement that counted now. He kept driving and did not look back, and the two superimposed worlds collapsed into one, and the one was simply this: a road, a truck, two people, morning coming up over the plains, the future unwritten and the past receding into the flatness of the Midwest, where sooner or later everything that had been built became indistinguishable from what had been left behind.