‘Who’s that?’ Ben asked.

‘I don’t know him,’ she said. She clicked again. The old man disappeared and a new picture filled the screen. It was of a white stone building that looked to Ben like a small temple or some kind of monument. It had a domed top and a classical frontage. ‘This I recognize,’ she said. ‘Ravenna, Italy. That’s Dante’s tomb. I’ve been there.’

‘Why would Oliver go to Italy if his research was in Vienna?’

‘I don’t know.’

‘Did Mozart spend a lot of time in Italy?’

She thought for a moment. ‘If I remember rightly from music school, I think he spent some time in Bologna in his teens,’ she said. ‘But apart from that, I don’t think he did more than travel there occasionally.’

‘This isn’t helping us,’ Ben said. ‘Move on to the next one.’

Click. The next picture showed Oliver at a party with two pretty girls, one on each arm. They were kissing him on the cheeks as he happily toasted the camera with a cocktail.

Leigh clicked again. It was another shot from the same party. This time Oliver was sitting at a piano. On the double stool next to him sat a younger man, mid-twenties or so, and the two were playing a duet together. They seemed to be having a good time, Oliver’s face caught in mid-laugh as he hammered the keys. Around the piano there were women in party dresses, resting on it, watching him play, smiling at him, smiling at one another, drinks in their hands. Faces were glowing. It was a very natural shot of happy-looking people enjoying themselves.

Leigh couldn’t look at it for long. She clicked and moved on.

A shot of a snowy village flashed up. There were trees and mountains in the background, laced with white. Leigh frowned. ‘Switzerland?’

Ben studied it. ‘Could be. Or it could be Austria.’ He reached across, clicked and scrolled down to reveal the properties of the picture. It had been taken three days before Oliver’s death.

Leigh sighed. ‘Still doesn’t tell us anything.’

Ben walked away from the desk and left her to browse through the rest of the photographs. He went over to the bed, sat down and drained his glass in one swallow. Beside him, spread out on sheets of newspaper laid across the bed, were the charred remnants of the box-file’s contents. Sifting through them gingerly, he turned over one of the papers and winced as it crumbled away at the edges.

Underneath it he saw the burnt, tattered remains of a document that looked different from the others. The fire had eaten away most of the text in black-edged bites that looked like missing pieces from a jigsaw puzzle. Nearly all the rest was so charred that the German handwriting was barely readable. All that was left were a few disjointed phrases that meant nothing to him.

For an instant Ben thought he was holding the original, and he caught his breath. No. It was just a photocopy.

It was the Mozart letter. Richard Llewellyn’s discovery. Oliver had told the story so often that Ben still remembered it clearly.

Many years ago, the Llewellyn antique piano restoration workshop and showroom had been situated in a busy street in the centre of Builth Wells. After the death of his wife Margaret in 1987, when Leigh had been thirteen and Oliver seventeen, Richard Llewellyn had gone into decline and taken his business with him. He was drinking too much to do his work well. Custom had tailed off dramatically. Then one day a chance find in the attic of an old house promised to change Richard Llewellyn’s fortunes forever.

The decaying pianoforte had been made in the early nineteenth century by the celebrated Viennese craftsman Josef Bohm. It had travelled to Britain sometime in the 1930s and fallen out of use a long time ago. It hadn’t been stored very carefully Woodworm had infected much of the casework and it needed a major overhaul to get it back into prime condition. But even in that poor state it was one of the most beautiful instruments that Richard Llewellyn had ever come across, and he was excited by the price it might fetch at auction once it was restored-maybe ten thousand pounds, maybe even more. He put away the port and sherry bottles and got to work.

He’d never finished the job. It was while restoring one of the instrument’s legs that Llewellyn had made his discovery. The leg was hollow, and inside it he found a rolled-up document, old and yellowed and bound with a ribbon. It was a letter written in German, and dated November 1791.

When Richard Llewellyn had seen the signature at the bottom, his heart had almost given out.

The last surviving letter written by Wolfgang Amadeus Mozart before his death just weeks later. How it had found its way into the hollow piano leg was a mystery, and would remain that way forever. All Llewellyn knew was that he’d found a historic treasure that was going to change his life.

At the time, the discovery had been all Oliver could talk about. His father had taken his prize to London for the scrutiny of expert musicologists and antiquarians. But his vision of the fortune the Mozart letter was going to earn him crumbled away when the experts declared it a fake.

‘Maybe it wasn’t, though,’ Ben said out loud.

Leigh turned with a quizzical look. ‘Maybe what?’

‘Your dad’s letter. Is it possible it wasn’t a fake after all, and that’s why these people are after you? What would it be worth?’

She shook her head. ‘Dad sold it, remember? Maybe you don’t. Years ago, about the time we stopped seeing each other.’

‘Someone bought it, even though nobody believed it was genuine?’

‘Yeah.’ She smiled. ‘Just when Dad was becoming completely despondent about the whole thing, this crazy collector got in touch with him. An Italian music scholar. He made an offer for the letter. It wasn’t the kind of money Dad had dreamed of, but he accepted it right away. Then the Italian said he wanted to buy the old piano, too. It was only half-restored but he paid top dollar for it anyway. I remember it being crated up and taken away in a big van. Then Dad was solvent again. He was still hurting over the response from the experts, but at least he had some money in his pocket. That was how I was able to go to New York, to study at the music academy.’

‘What was the Italian’s name?’ Ben asked.

‘I don’t remember,’ she said after a moment’s thought. ‘It was a long time ago, and I never met him. Oliver did. He said he was ancient. I suppose he’d be dead by now.’

Ben put down the fragment of the photocopied letter and sifted through some of the other documents. Something caught his eye and he looked more closely.

The fire had eaten away the right margin of the lined notepaper. The scribbled writing on the page was Oliver’s. Ben’s eye followed a line that was written in large bold capitals, triple-underlined as though out of frustration. The end of the sentence was burnt away where the paper had darkened from yellow to brown to crumbled ash. ‘“What is the Order of R-?”’ he read aloud. ‘Do you know what that might be?’

‘I haven’t a clue.’

He chucked the sheet down with the rest of the papers. ‘Shit. What a mess.’

Leigh had finished going through the photographs. There was just one file left on the disc. He leaned on the back of her chair as she opened it up.

‘It’s not a photo file,’ he said. ‘It’s a video-clip.’