Once into the apartment, she crept furtively from room to room. There was no sign of life. But a near-empty cup of coffee on the table, next to the remains of a meal, was still warm to the touch and the laptop on his desk was running. He must have just gone out, she thought. And if that was the case, it had to mean he was all right. She felt relief unstiffen her muscles. Maybe he wouldn’t be long.

The phone suddenly rang, making her jump. After two rings the answering machine came on automatic ally. Michel’s familiar mumbled recording came over the speaker, followed by a beep, and then the caller left their message.

She listened to the deep, gravelly French voice. ‘This is Saul. Your report has been received. The plan has been carried out. BH will be taken care of tonight.’

What was going on here? What report? What had Michel been sending, and to whom? Was this guy, her friend and assistant, someone she trusted-mixed up in this too? The plan has been carried out. She shivered. Did that mean what she thought it meant?

She walked over to the desk and flipped up the lid of Michel’s computer. The machine was on standby, and whirred quickly into life. She double-clicked on the email icon on the desktop. Her head swam as she scrolled down through the SENT ITEMS list. It didn’t take her long to discover the whole column of sent messages marked REPORT. They were numbered in consecutive order and dated from a few months ago to the present. Running down the list she saw that they’d been sent at regular intervals of about two weeks.

She clicked on a recent one, number 14. It flashed up on the screen and she scanned through it. Her heart picked up a beat. She sat on his desk chair and read it again, more slowly, hardly believing what she was seeing.

It was a report on her latest scientific findings, her breakthrough with the lifespans of the group A flies. It was all there, down to the last tiny detail. Her heart beat faster.

She opened the most recently sent post. It was dated that day, sent just an hour or so ago. It had an attachment with it. She read the accompanying message first: Today, 20 September, meeting with English journalist Ben Hope. Shaking her head in bewilderment, she clicked on the paper-clip logo in the corner of the message. As the attachment opened up she saw that it contained a series of JPEG files, digital photos. She clicked on each one in turn, and her frown deepened with every click.

They were shots of her and Ben Hope in her lab. They’d been taken just that morning, and there was only one person who could have done it. Michel, using his phone while he’d been pretending to fetch a file.

BH will be taken care of tonight, the phone message had said. And now she knew who BH was.

She stiffened and looked up from the screen. She’d heard something. Someone was approaching the front door. She recognized the familiar tune that Michel often used to whistle to himself at the lab. Keys jangled at the lock, and the door creaked open. Footsteps came down the hall. Roberta dived behind a couch and crouched there, hardly daring to breathe.

Michel came into the room. He was carrying a shopping bag, and as he whistled his little tune he started unloading groceries. He reached out and played back his phone message. Roberta peeked over the top of the couch and watched his face as he listened to Saul’s voice. There was no emotion, just a nod.

Her mind was racing, dizzy at the thought that this was the same Michel she knew. She ought to challenge him, have it out with him right here. But it was becoming clear that she didn’t know him as well as she thought. What if he had a weapon? Maybe confrontation wasn’t a good idea.

He deleted the phone message. ‘Christ, it’s warm in here,’ he muttered to himself. He opened a window across the other side of the room. Then he grabbed a chocolate bar and a bottle of beer from the grocery bag, flopped down in a chair and switched on the TV with the remote. He sat chortling at a cartoon and sipping his beer.

This was her chance. She ducked back down and started crawling out from behind the couch, keeping low. She was going to crawl right across the room and make it out through that open window while he was distracted by the television.

She was half out from behind the couch when he shouted, ‘Hey! What are you doing there?’

He rose from his chair.

She didn’t dare to look up. Shit, I’m caught.

‘You come down from there, now,’ he was saying in a gentler voice. She looked up, startled and confused.

He was across the other side of the room, by the desk. ‘Come on, my baby, you shouldn’t do that.’ A fluffy white cat had jumped up on the desk and was licking out the plate that he’d left sitting there from his earlier meal. He picked it up in his arms, stroking it lovingly. It meowed in protest and wriggled free of his grip, jumped down on the floor and ran out of the room. He ran after it, nursing a scratched finger. ‘Lutin! Come back!’ He disappeared out of sight and Roberta heard him shouting at the cat. ‘Lutin-come out from under there, you little turd!’

Seeing her chance, she leapt to her feet and dashed up the short passageway to the front door, silently turned the latch and slipped out.

When Michel Zardi had first been contacted a few months earlier by the man he knew only as ‘Saul’, he’d no idea who was approaching him, or what they really wanted. He only knew he was being asked to observe Roberta Ryder’s work and send back reports on the progress of her research.

Michel wasn’t an idiot. He’d been with her project from the start, and he had a pretty good idea of its potential value if she could convince anyone to take it seriously. Now it looked like someone was, although it wasn’t the kind of attention that Roberta would have wanted. Michel was smart enough not to ask too many questions. What they wanted him to do was simple enough, and the money was good.

Good enough to make him start thinking that maybe he didn’t want to spend the rest of his life bumming around as a low-paid lab tech, especially now that Roberta had been forced to relocate her operation to her own apartment. The project wasn’t going anywhere, they both knew that. He also knew her well enough to know that she’d never accept the reality. Her stubborn pride was what kept her going, but it was also going to drag them both down.

For a long time, Michel had toyed with the idea of leaving and getting better work elsewhere. Just when he’d been on the brink of telling her it was over for him, Saul had turned up out of nowhere. Suddenly, everything had looked different. The promise of a more stable and interesting future working for Saul and his people, whoever they were, meant that he had prospects. And it had helped to harden his attitude towards the American scientist he’d once thought of as his friend. Every couple of weeks or so he’d send in his report, and at the end of each month the cash-stuffed envelope would appear in his mailbox. Life was good.

It was a pyramid of power, broad at the bottom, small at the top. At the bottom, it was made up of lots of ignorant, insignificant men like Michel Zardi-little men whose loyalty could be bought cheaply. The top of the pyramid was occupied by just one man and a select group of his close associates. They were the only ones who knew the true nature, purpose and identity of the organization that so carefully kept its activities hidden from prying eyes.

The two men at the top of this pyramid were now sitting together in a room talking. It was no ordinary room, situated in the domed tower at the centre of an elegant Renaissance villa outside Rome.

The big authoritative man standing by the window was called Massimiliano Usberti. Fabrizio Severini was his private secretary and the only man Usberti trusted completely and spoke openly with.