‘A codename, issued June 2014. Perfect Vision.’ He waited. ‘Heard of it?’

‘No. It sounds like software, a program of some kind.’

‘That may be the idea. It sounds like software, but it’s a hell of a lot more. Tom Marsh got a lead from an internal directory. I ran the name against what I could. The budget for Perfect Vision is hidden in Requirements and Production, but it’s around seventy million over two years, including the use of Building D in Shefford Park. Building D had 130 members of staff cleared for entry at the peak of the operation last year.’

‘That’s huge.’

‘Huge, maybe compartmentalised. I doubt many of them knew what they were working on.’

‘What kind of staff?’

‘A lot seconded from GCHQ. Others, from what I can tell, were academics – psychologists, an anthropologist, historians; experts in China, Russia, Central Asia. I’ve tried to get hold of them but every single one is incommunicado. It was officially designated a research group, but the security set-up suggests it was operational. It wasn’t just producing papers.’

I thought back to Marsh’s account, the isolation of this unit: separate entrance, separate canteen.

‘Who ran it?’

‘It bypassed all the usual committees. There was Defence Intelligence involvement, so clearly the MOD was on board, but no one there has heard of it. Like Tom said, six months ago it disappeared as fast as it had arrived, a few days before Joanna ran away. What have you found?’

I said I had some leads, which felt optimistic. I told him I’d run into some trouble and had had contact from Russian intelligence.

‘Surely that’s a sign we need to pack it in,’ he said. ‘Come back. Get yourself killed on home soil, at least.’

The levity didn’t conceal his fear. I said I’d take one final look around while I was here. When he’d rung off I found ‘helping man’ on my phone, memorised the number before deleting it, then went to a phone box and dialled.

TWENTY-FOUR

Lieutenant Shomko answered brusquely. When he learned who it was he told me to wait, and moved somewhere quieter.

‘Who are you?’ he said.

‘We met last night.’

‘I know we met. I asked: who are you?’

‘I’ve got an offer for you. Meet me and I’ll explain.’

‘I cannot meet you.’

‘Two hundred dollars, just to hear me out.’

There was exhalation, some cursing in Russian.

‘Five hundred,’ he said.

Good man, I thought. ‘Four.’

‘Okay. You bring the money. You mess me around, I arrest you on the spot.’

‘Deal.’

He named a bar a long way away from the centre, said he couldn’t get away from work for a couple of hours. That gave me time to prepare.