‘There’s no proof MI5 has been compromised.’ Knox was aware he sounded like Peterson when he’d voiced the exact same idea to him outside the Fountain.

‘Well you sure are acting like there is, and here’s the evidence,’ Bennett said, pointing at the photo of Valera.

‘That’s a big leap,’ he said, covering his relief with another swig of coffee.

‘This is a big problem.’ She wasn’t smirking any more. ‘We were watching Bianchi and Moretti too. They were murdered, and now there’s a Russian genius in the same field suddenly in play. There’s no way they aren’t connected.’

Bennett had made the link herself the night before. It was what made her finally decide it was time to talk to Knox.

‘And, for argument’s sake,’ Knox replied, ‘so what if they are?’

‘We’re peering through the keyhole of a door that’s about to be thrown open. Whoever is at the front of this technology will have the power to spy on anyone, anywhere, any time.’

‘Big Brother isn’t real,’ Knox said.

‘Not yet he isn’t,’ Bennett replied. ‘But one day he will be. If we’re lucky it’ll be a friendly face watching over us. But what if it isn’t? Living under constant surveillance. No more privacy. Never knowing who we could trust.’

If Knox had any other job, he’d think she was crazy. But he was a spy, and as alarmist as he thought Bennett was being, he knew what she was suggesting wasn’t beyond the realms of possibility.

‘You can’t stop progress,’ he said after a moment, now repeating the phrase White had used on him countless times over the last six months whenever he’d expressed doubts about Atlas.

‘No,’ she replied between sips of coffee, ‘but you can guide it in the right direction. Make sure the right people are in control.’ She picked up the photo of Valera. ‘This will be circulated to the heads of MI5 and Six this morning as part of our regular information exchange. By now, the Russians will have realised one of their prized scientists is missing, and they’ll want her back. If they’ve turned someone here, they’ll send them after her. But if we get Valera first, we can secure a vital asset for both our countries, and set a trap for the mole.’

That felt less like fiction to Knox. If this woman was as important as Bennett believed, the KGB would do everything they could to stop her spilling her secrets. And if those secrets were as potentially world-changing as Bennett thought, every Soviet agent west of the Iron Curtain and north of the Alps could be put on her tail.

‘If there is one,’ he said.

‘If,’ she repeated, the smirk back on her face.

‘But why come to me?’ he asked. ‘Why not keep this in Grosvenor Square?’