The Book of Secrets

XXIX

Paris

The Institut Georges Sagnac occupied a low concrete campus in a western suburb of Paris. Plastic blinds covered most of the windows; the few rooms with lights on shone like television screens. A group of teenagers skateboarded on one of the access ramps, but otherwise there was no one to be seen.

Nick and Emily stopped in front of one of the buildings and rang the bell marked VANDEVELDE. The plastic housing on the intercom was cracked, the speaker muffled by a collage of faded stickers advertising underground bands, radical politics, bleeding-edge art or simply proclaiming anarchy.

‘Oui?’

Emily leaned closer to the wall. ‘Professor Vandevelde? It’s Dr Sutherland.’

A noise like a buzz saw ripped through the speaker. The door clicked open.

‘Venez.’

The elevator was out of order; they took the stairs. Professor Vandevelde’s office was on the fourth floor at the end of a long linoleum corridor that probably hadn’t been refurbished since 1968. They knocked, and a brisk voice summoned them in.

It was a large office. To the left, a broad window offered bleak views of the tower blocks which barred the horizon. There was a wood-veneer desk littered with papers, a whiteboard scribbled with half-erased equations and two low chairs. Yellow foam poked out of holes in the seats. The only decoration was a poster taped to the wall, a page from an illuminated manuscript advertising a long-gone exhibition at the Louvre.

Professor Vandevelde stood and came around the desk to shake hands. He was a tall heavyset man, dressed in cord trousers and a blue sweater, his shirtsleeves rolled up over the arms. Apart from the silver-rimmed spectacles he wore, Nick thought he looked more like a fisherman than a physicist.

‘Emily Sutherland,’ said Emily. ‘This is my assistant, Nick.’ Vandevelde flipped on a kettle balanced on top of a grey filing cabinet. He motioned them to sit.

Emily perched on a chair and crossed her legs. ‘Thank you for seeing us at such short notice, and on a Saturday afternoon. I’m so sorry my email never arrived.’

Vandevelde wiped a spoon on his sweater and opened a jar of Nescafé. ‘ça ne fait rien. I am here anyway. And you have come all the way from the Metropolitan Museum in New York.’

‘I’ve read so many of your papers.’ Pulled off the Internet in a smoky café and skimmed in the time it took to finish an espresso. ‘But my colleague struggled to understand the process.’

Nick smiled apologetically as if to say he didn’t blame Vandevelde.

‘I wondered if you could explain for him.’

‘Of course.’ The professor stood and ushered them through a side door into a plain windowless room.

‘This is where we have the proton milliprobe.’

The machine looked like something out of a dentist’s surgery: white metal pipes sticking out of the wall and the ceiling, ending in a nozzle that pointed at a steel lectern. A bundle of thick cables snaked away from it to a computer on a desk against the wall.

‘What we are doing, it is called PIXE technique. Particle-induced X-ray emissions.’ He exaggerated each word so slowly that with his thick accent they became almost unintelligible. ‘It has been developed in San Diego in the 1980s. What you are doing is to fire a beam of protons through the pipe – ici – into the object you analyse. In my experiments it is a page from a book. The protons, they pass through the page, they hit the atoms and they break them. This release the X-rays, who we measure with a fluoroscopy system.’

He tapped the nozzle suspended from the ceiling, then pointed to the computer. ‘It analyse the emission and tell us what is inside the page.’

‘Doesn’t that damage the book?’

‘Non. We scan only one millimetre of the page and the protons break only a few atoms. Except at the molecular level, there is no damage.’

Nick glanced at Emily. She seemed happy for him to continue with his questions. ‘And this tells you what’s in the paper?’

‘It tell us what is in the ink. Every ink have a chemical signature we identify. We analyse the early printed texts so that we see who have made them.’

Nick took a deep breath and reached into his coat. ‘So what did you find when you scanned this?’ He held up the card, keeping his eyes fixed on Vandevelde’s.

‘I work only with books. I have not analysed this card.’

But Nick had seen it on his face – recognition, and something else. Fear? ‘A woman called Gillian Lockhart brought this to you.’

‘I have never seen this Gillian Lockhart.’ He said it in the same laboured way he had explained the PIXE acronym earlier, something memorised.

‘What did you find?’

‘I have told you. I have not ever seen this before.’ Vandevelde stood. ‘I think perhaps you are not interested in my work. I am sorry, I cannot help you.’ He put his hand on the door. ‘S’il vous plaît…’

Nick and Emily stayed where they were. ‘When did Gillian come here?’

‘Never.’

‘She called you a month ago. Three weeks after that, she disappeared. ’

Vandevelde sighed. ‘I am sorry to hear this. Truly. But – I cannot help.’

‘Do you remember her calling you?’

‘What do you say is her name?’

‘Gillian Lockhart.’

Vandevelde shook his head a fraction too soon. ‘Non.’

‘We have her phone records. The conversation lasted almost fifteen minutes.’

‘Perhaps my secretary have put her on hold while she look for me. Perhaps she does not give me her name – or not her actual name. Perhaps she pretend she is interested in my work because she want something else.’

He let go the door handle and walked back to his machine. ‘You think I hide something from you? I hide nothing. I promise to you I have never seen your friend, or this card. But if you want for me to analyse it, if this makes you happy, I do it. Oui?’

He held out his hand, his head cocked to one side. Nick glanced at Emily, who nodded cautiously.

The Frenchman laid the card flat on the lectern in front of the pipe, then fussed with the nozzle until it was aligned to his satisfaction. Nick leaned in and squinted.

‘It’s pointing at nothing.’

‘We take two measurements. The ink is absorbed in the paper, yes? So first we measure the paper by itself, then with the ink. If we subtract the first measure from the second, we have left only what comes from the ink.’

He turned a handle to lock the nozzle in place, then crossed to the computer. Nick still crawled with misgivings. ‘Do we have to leave the room or anything?’

‘It is very safe. You absorb more protons standing fifteen minutes in the sun. If you do not trust me, you can be holding the card all the time I do the experiment.’

Nick took a step back. ‘I’ll watch from here.’

There was almost nothing to see. Vandevelde pressed a key on the computer; there was a rumbling sound from behind the wall, and a red light went on over the pipe. Seconds later, the light went off and the rumbling stopped. Vandevelde readjusted the nozzle so that it now pointed at a luxuriant part of a lion’s mane, where the ink was thickest. The light blinked on again, then off. A jag-toothed graph appeared on the computer screen.

‘What does that mean?’

‘It shows the different elements we can detect.’ Vandevelde traced one of the sharp peaks with his finger. ‘This line shows the sodium content. This is the copper.’

‘So… what? You can figure out what the ink was made of?’

‘Not all of it. Some elements the X-ray fluoroscopy system cannot measure. Sometimes we do not know where it has come from. For example, we find lead. Perhaps it has come from massicot, which is an agent for the drying; or it has come from a heated lead oxide for the colour; or – if it is a book – it has rubbed off from the lead alloy types. All we can say with this machine is there is lead.’

‘So what’s the point?’

‘Every ink have a signature, you understand? Every printer, he uses a different ink. We have a database.’

‘Can you check this ink?’

‘Bien sûr. I show you.’

He pressed a button on the computer. An hourglass spun lazily over the graph. A few seconds later a single line of text appeared at the bottom of the screen. Nick guessed what it meant even before Vandevelde gave his one-word summary.

‘Rien.’ He shrugged and edged away from the computer. There was a wariness in his movements, Nick thought, like a dog that has been kicked too often. He gave Nick and Emily a sad look. ‘If your friend have come here – and I promise she did not – I would tell her the same.’

Nick took the card off the lectern, wrapped it in the tissue paper and put it in his bag. He stared at Vandevelde, certain that there was more but unable to think of anything to say.

Vandevelde opened the door and gave a sad smile. ‘I hope you find your friend.’

Reluctantly, Nick stepped into the dark corridor. As Emily followed, Nick heard Vandevelde mutter something to her in French before he shut the door. They walked down the stairs in silence. Outside, the sun had set and the skateboarders had gone. The only light now came in orange pools under the street lamps. The air was bitterly cold.

‘What did he say when you were leaving?’ Nick asked.

‘He said, “Not all the marks on the card are ink.”’

Nick glanced back, wondering what it meant. But when he looked up, the room on the fourth floor was dark.