Unit 14

Dov Ferreiro had been a fire investigator for the city of Port Alder for seventeen years, and the first thing he did at any scene was to stand still in it for ten minutes without touching anything, which the crews found eccentric and which had made him, by a margin nobody at the service bothered to dispute, the best they had.

Unit 14 at Dunmore Wharf was a steel-framed transit warehouse of about four thousand square metres, built in the seventies, re-clad twice, and let for the last six years to a logistics company called Verrow & Kinsella. It had burned for nine hours on a Thursday night in November and the roof had come down over two-thirds of the floor and there was nobody inside it, which was the only genuinely good news anybody had that week.

He stood in it for his ten minutes at half past seven on the Friday morning with the rain coming through what was left of the roof and the whole place ticking as it cooled, and what he was doing, which he has never successfully explained to a jury, was letting the building tell him where it had wanted to burn and where it had been made to.

A fire in an empty steel warehouse is a lazy animal. It goes up, it goes along the ceiling, it looks for fuel, and if there is no fuel it gets bored and dies. This one had not been bored. It had started in the northeast corner in a partitioned block of offices, and it had stayed there long enough to take the partition down to the slab, and only then had it gone up and along and out into the rest of the shed.

Seventeen years had taught him that a fire that spends that long in one corner is a fire that has been given a reason to. He photographed the pour pattern on the slab, which was there, and which was not subtle, and which somebody had made no effort at all to hide, and that was the second thing that bothered him about Unit 14 before eight in the morning on the first day.

The first thing was that the shed was empty. Not damaged-empty. Not burned-out-empty, which looks like a great deal of black rubbish. Empty in the way a shed is empty when there has been nothing in it: no pallet residue, no racking bolts sheared off at the slab, no melted shrink-wrap in the drains, no lines of soot shadow where stacked goods had shielded the floor. Four thousand square metres of nothing having been there.

He wrote the word empty and underlined it and then sat back on his heels in the wet and looked at four thousand square metres of clean slab, because a warehouse is a business that exists to have things in it, and a warehouse with nothing in it is either between contracts or lying, and Verrow & Kinsella had eleven staff on the payroll and sixty clients on the letterhead.

He was writing that down when a woman in a very good coat and entirely wrong shoes came through the personnel door behind him and said, without introducing herself, "Do not move anything in the northeast corner, please, I need the filing."

Her name was Halina Zambrano and she was a forensic accountant, and she had been sent by the syndicate that carried forty per cent of the risk on Unit 14, and she had been on a train since half past four.

Dov, who had spent seventeen years learning to be polite to insurance people at eight in the morning, told her that the northeast corner was where the fire had been set, that it was a crime scene rather than a filing cabinet, and that she was standing in his pour pattern.

Halina looked down at her feet, moved four paces to the left, and said, "Set. You are saying set on day one? Before the lab?"

"I am saying it to you, in a shed, off the record, because you will find out in six weeks anyway and because I would rather you started from the truth." He put the camera down. "There is an accelerant pour in the corner, it is not disguised, and the shed is empty and has been empty for a long time. Whoever did this did not care whether we knew it was arson. They cared about that room."

And Halina Zambrano — thirty-eight, eleven years at a loss adjuster after four at a bank she does not discuss, carrying a bag with three laptops in it because she does not trust any one of them — stood in the wet ash of a burned-out office block in a warehouse on Dunmore Wharf and said the sentence that started all of this: "Then it was not a fire. It was a deletion."

They disagreed about the next thing and about almost every thing after it. Dov's position, then and for eleven weeks afterwards, was that a fire is a physical event with a physical cause and a physical perpetrator, and that his job was to find the person who had stood in that corner with a container, and that everything else was motive and motive is for the prosecution.

Halina's position was that anybody can be paid to stand in a corner with a container, that the person who stood there was almost certainly the least interesting individual involved, and that the only durable evidence in a case like this was not in the building at all but in the accounts of nine other companies who had never heard of the fire.

The company was forty-one years old, had eleven employees, and moved bonded goods in and out of Port Alder for about sixty clients, which is an entirely ordinary business and one that half a dozen firms in that city do.

Its managing director was a man of sixty-three called Ruaidhrí Kinsella, who arrived at Dunmore Wharf at ten past nine on the Friday morning in a state that Dov described in his notes as appropriate and that Halina described in hers, on the same day, as rehearsed to the point of being a performance of appropriate, which is the first written record of the two of them disagreeing about a person.

Kinsella was cooperative. That is important and both of them agree on it. He gave them the lease, the insurance, the alarm contract, the staff list and a shed key that opened nothing any more, and he answered every question either of them asked for two hours in a portacabin with the rain on the roof.

What he said about the contents was that Unit 14 had been cleared in September for a re-fit that had then been postponed, that the goods had gone into two other sheds, and that the only thing left in the building on the night of the fire was the site office and its filing.

Halina asked what filing. Kinsella said the usual: gate records, weighbridge tickets, the surveyors' certificates, the warehouse receipts, forty years of it, all of it duplicated electronically and none of it worth burning a shed for.

"Duplicated where?" said Halina. And Kinsella said, on the server. And Halina said, where is the server. And Ruaidhrí Kinsella, sixty-three, managing director, in a portacabin in the rain, said that the server had been in the site office in Unit 14, in the northeast corner, and then heard himself say it, and stopped.

Dov Ferreiro has said since that he learned more about his own trade in the four seconds after that sentence than in the previous nine years, because he watched a forensic accountant not react at all — no pause, no glance, nothing — and simply ask the next question, which was whether the alarm contract covered the office block separately, and which was of no importance whatsoever, and which gave the man in front of her forty seconds in which to decide he had got away with it.

They went their separate ways at four on the Friday afternoon with two different lists and a mutual conviction that the other one was going to waste a fortnight.

Dov's list had six things on it and all six were physical: the accelerant, the container, the point of entry, the alarm log at the monitoring centre, the CCTV on the wharf road, and the question of who had a key. He worked it the way he had worked a hundred and forty scenes, which is slowly and in order, and he was still on item three on the following Wednesday.

Halina's list had one thing on it. She wrote it on the train home, on the back of the lease, and it said: What document existed in Unit 14 that does not exist anywhere else?

Because that was the whole of it, she says, from the first hour. If you burn a building to destroy a paper, then the paper is a paper that cannot be destroyed any other way, and in her experience of eleven years there are not many of those. A contract exists in two copies at least. An invoice exists at both ends. An email exists on a server owned by somebody in another country who does not care about you.

The documents that exist in only one place are a small and specific family, and she could name them in her sleep: original bearer instruments, wet-signed guarantees, and — in a bonded warehouse on a wharf — the warehouse receipt.

A warehouse receipt is a piece of paper that says a named quantity of a named commodity is physically present in a named shed and is held to the order of whoever holds the paper. Banks lend against them. They lend a great deal against them, quickly and cheaply, because a warehouse receipt is supposed to be the closest thing in commercial life to the goods themselves.

She had spent four years, earlier in her life, on the other side of exactly this, in a department at a bank where warehouse receipts arrived as attachments and were checked against a template by people with nine minutes to spend on each, and she does not discuss those four years, and everything she is good at she learned in them.

She got off the train at half past six, walked home in the rain in the wrong shoes, and sent Dov Ferreiro the first of the two hundred and forty messages they exchanged over the following year. It said: Your shed was empty and its receipts burned. Ask me what those two facts are worth together. He replied at eleven the next morning, having thought about it for sixteen hours, with one word, which was: Ask.