by Adam Blake
‘This is the Kelvin probe?’ Kennedy asked.
‘This is just the scanning head,’ Partridge said. ‘There are a lot more components. They’re parked in a van three streets away – closest we could get. My God, I hate this city.’
‘That just makes you a bigger hero, John.’ Kennedy turned to the young man and woman. ‘And I assume you two are the operators. Thanks so much for taking the time to do this.’
‘Actually, we’re graduate students,’ the woman – Kathleen – answered. Her voice had a Welsh accent so delicate and musical that it sounded as though she were reciting a poem. ‘But we’re qualified to use the probe. We’re both doing research in force microscopy.’
‘And the university couldn’t spare anyone from the faculty,’ Partridge summed up. ‘So William and Kathy kindly agreed to come down to the Smoke for the day and help you out. In exchange for their travelling expenses and a small per diem.’
‘Of course,’ Kennedy said. ‘I’m grateful to you both. Really. This is just wonderful.’ She didn’t think Emil Gassan would object to the extra expense, but if he did, she would meet it herself out of the money she’d already been paid.
‘Let’s go in,’ she suggested. ‘I’ll see about getting you some coffee, and then I’ll explain what it is I need.’
‘We might just as well skip the coffee,’ Partridge suggested, as the two students hefted the steel case by its evenly spaced handles and raised it between them like pallbearers raising a coffin, ‘and get straight down to business.’
But they couldn’t do that without explaining to Gassan, and he was rattled all over again when he realised what he was signing up to. ‘Are we sure that this is legal, Heather?’ he asked, drawing Kennedy aside. ‘It sounds as though it might raise issues of privacy and freedom of information.’
‘These are your premises,’ she explained. ‘All we’re doing is examining them for evidence of unauthorised access. We’re not assuming criminality, only trespass. We’re going to look around Room 37 and find out what was done there. Then when we brace our suspect, we’ll have some ammunition. This was a professional job, Emil. He won’t cave, he’ll stonewall you to the last inch. If you want to have any chance of finding out what happened that night, you’ll need to have a good part of the answer before you ask the question.’
She waited while Gassan thought it through, but she knew she was right and she didn’t have any doubt as to what he’d eventually decide. ‘All right,’ he said at last. ‘Let’s do this.’
At Kennedy’s suggestion, they brought Rush in to help the two students ferry the rest of the components from Partridge’s van. While they were unpacking and setting up, Kennedy tried to explain to Gassan what the probe actually did, but very soon ran into the limits of her own understanding, and Partridge had to come to her rescue.
‘In the 1980s,’ he told Gassan, ‘two Swiss scientists developed a new kind of microscope, one that could scan at an atomic level. They called it AFM, atomic force microscopy. And they did great things with it. It could resolve images down to nanometer scales, with enormous accuracy. The only problem was that the image size, even for a single-pass scan, was colossal. So unless you were looking at incredibly tiny areas, it wasn’t feasible to use an AFM device.’
Away in the background, Kennedy could see Rush standing a little aside from the students. He was helping them whenever they needed him, passing them components from the boxes, holding the main body of the probe steady while Sturdy or Price connected a cable or a bracket to it. It was obvious that he was attracted to Sturdy – and that he had no chance at all because Sturdy and Price were already an item. The follies of youth, Kennedy thought.
She wrenched her attention back to Partridge, who was still talking about the Kelvin probe and its short but illustrious history. ‘But then,’ he said, ‘the University of Swansea got stuck into the original design and started to come up with some really sweet variations. They more or less invented a science called nanopotentiometry. It measures minute changes in electrical potential. The probe looks at the conductivity of an object’s surface. It creates a map of that electrical potential.’
Gassan was nodding, but his eyes were a little glazed.
‘You can use it for fingerprints,’ Kennedy told him, cutting to the chase. ‘It does a million other things, too, but for police it’s a fingerprint machine.’
Partridge looked pained at this oversimplification, but he nodded. ‘Traditional fingerprinting produces an image using oily residues from the skin surface. But those same residues alter the electro-magnetic profile of any object that you touch with your hands. So the Kelvin probe cuts out the middle man and looks at the conductivity of the object’s surface. It creates a map of electrical potential – on which fingerprints stand out like mile-high beacon fires. No need for developing or resolving agents. No need to touch the surface at all, so no danger of destroying or contaminating other kinds of evidence like DNA while you’re looking for a latent print. And you can programme it to recognise and respond to a specific print – your prime suspect, say. It’s like a magic lamp. Except it’s bloody hard to use, because you’ve got to adjust the sensitivity of the reader to a minute degree of accuracy to screen out other kinds of random or systemic variation in the electric field forces. Hence these two enthusiastic young people working their arses off in uncomplaining silence behind me.’
Kathy Sturdy and Will Price looked up, awkward and embarrassed, as Partridge gave them this accolade. They’d unpacked the components of the probe and assembled it beside its steel housing. Now Price was adjusting brackets and screws on its outer case, while Sturdy was taking readings from a small tablet computer that she’d attached to the device via an HDMI cable. Rush watched them, or at least he watched Sturdy, his expression rapt.
The scanning Kelvin probe didn’t look like a magic lamp. It didn’t look like a microscope, either. It looked like an artist’s impression of a vacuum cleaner from a sci-fi pulp published before vacuum cleaners had actually been invented. Every single component looked ramshackle and jury-rigged. The only high-tech thing about it was the image on the tablet PC, which formed and reformed itself out of bright-green grid lines from moment to moment.
Sturdy tweaked the image using virtual slide controls overlaid on it. She did this for a long time, before finally nodding to Price. He took the business end of the device – a scanning head about as long and thick as a foot ruler, attached to a three-metre length of cable – and ran it across a fire extinguisher mounted on the wall beside him.
The screen blanked, the gridlines reassembled themselves and a new image appeared. It was hard to make out what it was. Its planes of coagulated colour defied interpretation, until Sturdy, with a sweep of her hand across one of the sliders, caused the image to zoom out wide, revealing the curved surface of the fire extinguisher.
She zoomed in again and the surface dissolved into level upon level of fractal complexity.
‘Twenty?’ Price muttered to her. ‘Twenty-five?’
‘Twenty-five,’ she confirmed. ‘I’m going to heighten the contrast by half a per cent.’
‘Okay. Shall I hold steady?’
‘No, slow sweep. There. Up. Up by a couple of … stop.’
Price was pointing the scanner at the base of the fire extinguisher. Sturdy tapped and stroked with the tip of her index finger on the virtual controls. The screen blanked and remade itself in squares of a couple of centimetres on a side, settling to a preset level of magnification. Kennedy and Gassan found themselves staring at the raised whorls and ridges of a fingerprint.
‘And Bob’s your uncle,’ said Partridge, with some satisfaction.
‘My word,’ said Gassan, after a pause for genuine awe.
‘But that’s only the first battle,’ Kennedy reminded him – and the students. ‘There are going to be lots of prints in here. We’re looking for a particular set, and we’re going to give you a match in advance. Rush?’
‘Oh. Right.’ Rush reluc
tantly tore his gaze away from Sturdy. He reached into his pocket and removed a stainless steel fountain pen in a plastic evidence baggie. Kennedy had told him to go for something metallic if he could. The greater the electrical conductivity of a surface, the better the Kelvin scanner worked on it.
She took the bag and handed it to Sturdy. ‘How does this part work?’ Rush asked the student.
‘We find a print on the pen,’ she said, holding the bag gingerly by its corner, ‘and we enter it on the recognition software. Then we set the scanner to ignore anything that isn’t a match. Hopefully we’ll be able to get a full print off the pen, because then we’ve got the widest range for identifying partials.’
Kennedy turned to Professor Gassan. ‘And from that,’ she said to him, ‘we make an action-map of the room. We find out exactly where your intruder went and what he touched.’
‘Although that still won’t tell us if anything was taken,’ Gassan said doubtfully. ‘As we already discussed, Heather, this room is overspill from the British Library collection. We don’t have a catalogue.’
‘You busy, Rush?’ Kennedy asked.
Rush’s head snapped up. ‘Me?’ he said.
‘You.’
‘I … no. I’m good. What do you want?’
‘Go get me a catalogue,’ Kennedy told him.
10
It took three hours. Nobody at the British Library seemed to have the slightest idea what Rush was talking about when he mentioned the relic collection at Ryegate House. Or else they did, but they didn’t see any reason to let his problem become their crisis.
Finally, a bored clerical assistant found a third-generation photocopy of some pages marked on the first sheet in scrawled handwriting with the single word BOXED. ‘It might be this,’ he said.
It looked right, because it was broken down by room and the rooms were thirty-four to forty-one. It also looked piss-poor, because it was only broken down by room – not by aisle or box. But it was the best Rush was going to get, so he took it and went back to Ryegate House.
He found Partridge and the two students still scanning Room 37 while Kennedy was walking along the aisles laying Post-it notes down on the floor or affixing them to the shelf units, marking up the places where the Kelvin probe had already found matching fingerprints. Professor Gassan seemed to be present in a supervisory capacity – standing in a corner and watching with a mixture of fascination and concern.
Rush gave Kennedy the list and waited for her to fulminate in her turn, but she seemed unsurprised. She just nodded and handed it back to him.
‘Not a lot of use,’ he observed.
‘No,’ Kennedy said. ‘But I’d have been really surprised at this stage to get anything better.’ She glanced across at Sturdy and Price, who’d reached the end of the last shelf unit and were now scanning the further wall. ‘We’re almost done,’ she said. ‘We’ll go over this stuff right here, then we’ll bring our suspect up to the boardroom and brace him. I want you there, Rush – and Professor Gassan, and maybe your boss, Thornedyke. Apart from that, we’re still saying nothing to everyone else until we’ve got the full story.’
‘Okay,’ Rush said.
At the other end of the room, Sturdy looked around at them and waited politely to be taken notice of. ‘I think we’re finished,’ she said.
Kennedy went over and conferred with her, while Rush scanned the room. For the first time, he thought about what it was he was seeing here: a three-dimensional map of the intruder’s movements around this space. Or maybe four-dimensional, since the clustering of the Post-it notes presumably indicated how long he’d spent in each part of the room.
He looked at Kennedy, who had caught his glance and read it correctly. ‘It’s interesting, isn’t it?’ she said. ‘Everything comes back to this one area.’ She indicated the very end of aisle B, where Post-its grew in bristling thickets. ‘Whatever our intruder was interested in, it was definitely somewhere in this stretch. But he didn’t know exactly where.’
‘Seven boxes were handled extensively,’ Sturdy chimed in. ‘These seven here, all sequential, all grouped together. The rest weren’t touched at all, except for this one, right next to the others – a broad palm-print, which I think might mean that it was pushed to one side, out of the way.’
She looked at Kennedy as she said this, a little nervously, as though hypothesising might be Kennedy’s prerogative. Kennedy nodded encouragement. ‘That’s what I’d have said. So?’
‘So he knew what he was looking for, but not exactly where it was.’
Because he was working from this list, Rush realised, suddenly. And it breaks the books down by room, but not by box. Maybe he started at a random point, or maybe he took a guess based on the length of the overall list and the position on the list of the thing he wanted.
Which meant …
It came to Rush, then, that he’d had the whole thing arse-backwards all this time. He’d been assuming that the intruder had passed through Room 37 on his way out of the building and that his real business had been conducted somewhere else. But the clustering was a smoking gun.
The intruder was after a book, or maybe several books.
‘And the fact that he stopped after seven boxes,’ Kennedy pointed out, their thoughts running on parallel tracks, ‘means that he got what he came for.’
‘In box seven.’
‘This one.’ Kennedy laid her hand on the lid of it. ‘Emil, do you mind?’
‘Of course, of course.’ Gassan had been absorbing all this in fascinated, perturbed silence. He waved her on hurriedly. Kennedy opened up the box and slid out the first volume. It wasn’t really a book: it was a slender pamphlet, the paper foxed with age and ragged along every edge, in a stiff Mylar sleeve.
She held it up and showed it to them all. It was hard to tell what the title was. Everything was in the same font, but in a wide variety of point sizes, with italics thrown in seemingly at random.
A New-yeers Gift
FOR THE
PARLIAMENT
AND
ARMIE:
SHEWING,
What the KINGLY Power is;
And that the CAUSE of those
They call
DIGGERS
Is the life and marrow of that Cause the Parliament hath Declared for, and the Army Fought for
‘A New Year’s gift for the Parliament,’ Kennedy read aloud.
‘By Gerrard Winstanley,’ Gassan finished.
Kennedy scanned down the cover. ‘Yeah,’ she confirmed. ‘That’s the one. Do you know him?’
‘Winstanley was a Digger. They were proto-communists, at the time of the English Civil War. They believed in shared ownership of the land.’
Rush consulted the list. He found the pamphlet reasonably quickly. ‘Middle of the seventeenth century,’ he confirmed. ‘Sixteen fifty-two, according to this.’
Kennedy went back to the box and fished out the next book. Another pamphlet, very similar to the first both in appearance and in general condition: The Law of Freedom in a Platform, Rush read over her shoulder. She slid it back and took out another book, square-bound and obviously a lot more modern, entitled Political and Religious Extremism in the Interregnum. She turned it sideways on to read the catalogue number on its spine.
‘We might be in luck,’ she said. ‘It looks as though the books were put in the box in catalogue order. Now that we’ve got the list to cross-reference against, we’ve got a good chance of figuring out if anything is missing.’
‘Then let’s continue,’ Gassan said. He took the list from Rush’s hands, laying claim to it.
Kennedy took the box, Gassan read aloud from the list, Rush, Price and Sturdy watched in solemn silence and John Partridge retired into a corner of the room to light up a strictly illegal cigarette. It only took them ten minutes to get to the first missing item.
Title: A Trumpet Speaking Judgment, or God’s
Plan Revealed in Sundry
Signes
Author: Joh
ann Toller
Catalogue number: 174583/762
Date: 1658
It was the only missing item. From there to the end of the box, everything was in apple-pie order.
Rush was amazed. Mostly at the power and versatility of the Kelvin probe, but underneath that, he was amazed that anyone would go to so much trouble for a book.
‘I suppose it’s valuable,’ Kennedy mused. ‘It’s getting on for four hundred years old.’
‘Which is nothing,’ Partridge said drily. ‘I don’t know very much about the antiques business, obviously – not my field at all – but at a generous estimate I’d say that a book from that time would be worth … well, no more than a hundred thousand pounds or so. Professor Gassan, would you agree?’
‘I’m hardly an expert on the market value of these things,’ Gassan protested. ‘But I’d be surprised if that book was insured for more than fifty or sixty thousand.’
Rush thought about that. There were any number of other books in the box whose worth was likely to be at least as great, and they didn’t weigh all that much, so it would have been easy for the intruder to grab a handful of them and hit the road.
But they all knew, from the evidence of the fingerprints, that that wasn’t what had happened. You search through seven boxes, take one item, then stop: obviously, that one item was what you came for.
And then what? You burn it? Because what Rush had seen in that other box, a couple of aisles over, was definitely ash.
Gassan was looking at Kennedy expectantly. Now that she’d brought off this miracle, his expectations of her were clearly running very high.
‘Very well, Heather,’ he said. ‘You’ve gathered your evidence. I presume you have a plan for how to use it?’
‘I think we’re ready to meet our suspect,’ Kennedy said. ‘We’ll need to use the boardroom again.’