The patrols moved up, into a dead world of twisted smoking fragments, some made of iron, some made of steel, some possibly from a vehicle, some smaller pieces possibly from weapons. Piled everywhere was debris from the plane. No attempt was made to quantify human remains. It would have been a hopeless task. Dust to dust, ashes to ashes, literally.
The only remotely intact structure was a small concrete stair head bunker disguised to look like a stone house. The air force claimed ownership. The original plans were lost, but anecdotally it was known to have been built fifty years previously, to contemporary blast-proof construction standards. It had stood up well. The roof was damaged. The interior concrete was blistered and spalled and calcified, but still reasonably solid. There were three circular shafts dropping down through the floor. It was surmised that once there had been steel casings for two ventilation ducts, and a spiral staircase probably also made of steel, but they had first melted and then vaporized.
Which proved, the arson people said, that the fire had started underground.
They donned protective gear and were lowered what turned out to be a total of two hundred and ten feet into the earth. They found a sequence of small tunnels and chambers, more blistered and spalled and calcified concrete, some ash that might once have been organic, and, amazingly, more than one thousand intact diamonds.
The arson specialists set up shop in the Bolton police station and connected their laptops wirelessly to their mainframes back home. They started work. They drew three-dimensional models of the underground facility. They made some guesses and assumptions. They knew from police records that a pump truck had been stolen along with the de-icer. So, if the aluminum had been an aeroplane, and if there had been an underground storage tank, then the accelerant might have been jet fuel. Which was consistent with their estimates of the fire's temperature, the upper limit of which they felt was defined by the survival of the diamonds, and the lower limit by the fact that the snow on the ground had been melted for two miles in every direction.
Major Susan Turner saw the news every evening on the television, and read it every morning in the papers, and followed it all day on line. She stayed in her office in Rock Creek, waiting by the phone. She slept in her visitor chairs, leaning back in one, her feet up on the other. The phone never rang.
After a week the arson theorists presented their best guesses. The fire had been a refuelling accident. Possibly due to undischarged static electricity arcing between the plane and the hose, more likely due to vapour build-up underground and a spark from a boot heel on concrete. The fire had burned mostly two hundred and ten feet below the surface, with enhanced thermodynamic characteristics due to a strange aerodynamic stasis in which a gale of air had howled down the stair shaft and the products of combustion had blasted up the twin ventilation shafts, in exactly opposite directions but with perfectly equal masses and velocities, in what amounted to a controlled and everlasting explosion in a narrow vertical cylinder made of fireproof material. Like a rocket blasting off, but upside down, heading for the centre of the earth, not the sky. The roof damage was felt to prove it. Two temporary caps placed in the fake chimneys fifty years earlier had blown out and were found six hundred yards away. It was estimated that the narrow cone of flame might have reached a thousand feet above ground level, thereby mimicking the heat signature of a launching missile.
It was felt the initial phase of the fire might have lasted four hours. Then when the fuel load had depleted below a certain critical point the stasis had collapsed and a fireball had bloomed upward and outward, at a lower but still tremendous temperature, and had burned for an hour or so before collapsing again and finally burning out.
The toxic cloud in Bolton could not be explained. The air force admitted to storing surplus aircrew requirements from World War Two in the facility, all of it tanned leather in the form of helmets and boots and flying jackets, and it was felt that chemical residue from the tanning process might have been responsible for temporary adverse medical effects.
The presence of the diamonds was not explained, either. A theory was advanced that they had been stolen in Europe in the last days of the war, and entrusted to a quartermaster to be smuggled home, but had been mislaid and routed to the wrong destination.
After a series of discreet phone calls from the Pentagon, both the FBI and the local agencies in South Dakota concluded that in the absence of remains positively identifiable as human, no homicide investigation could be opened.
Two weeks later Kim Peterson moved with her children to a small rented house in Sioux Falls, to be nearer her father and their grandfather. Not exactly a teeming metropolis, but at least there were things to be seen from her kitchen window.
Four weeks later Susan Turner was deployed to Afghanistan. Elements of the 110th were operating there, and her presence was required. On her last day in Virginia she put Jack Reacher's old service file in a khaki envelope and marked it Return to Human Resources Command. She left it front and centre on the damaged desk. Then she walked out of the old Rock Creek office, and closed the door with the fluted glass window, and walked along the narrow linoleum corridor, and down the stone stairs, and out to her waiting car.