‘Yes,’ I said. ‘We are. And friends look out for each other, right?’

‘Right.’

‘We looked out for each other in the tunnels. And you’ve looked after me up here. But I can’t look out for you where I’m going … Man, I don’t even know where I’m going, never mind what I’m going to do when I get there. But you have to get away. Lie low, have a holiday. Right now, no one knows you’re involved in any of this. And believe me, that’s a really, really good thing.’

‘How much is it?’ he said, still refusing to look me in the eye. Even though we were standing a foot apart, I wasn’t sure he’d heard a word I’d said.

‘How much is what?’

‘The jet. How much does it cost? Expensive, I bet.’

‘Yes. It’s expensive. Where are you going with this?’

‘How much? Ten thousand dollars? Twenty?’

‘Sixty,’ I admitted. ‘It will cost sixty grand.’

Under the circumstances that was both exorbitant – I had no way of getting the fare that didn’t involve robbery – and supremely reasonable: how much is anyone prepared to pay for their freedom? In my case, right then, right there, the answer was, Everything.

‘OK. So, Mr Max, how are you going to pay your Israeli friend sixty thousand dollars when you have …’ he glanced at the money spread out on the table, ‘2,245 euros, and, ah, 100 dollars?’ He looked me straight in the eye then. ‘Tricky, huna?’

He bent down and leaned across me and opened a secure web browser on one of the laptops between us. Left-handed, he typed in a few strokes and turned the screen towards me, angling it back so I could read it standing up. It was an Ethereum cryptocurrency trading account. His holdings showed as 1,225.5 coins.

‘And?’

‘And I can pay for your flight. Our flight.’

I felt my estimation of his mental stability slipping. I needed to appease him. Carefully. As much as he could be a risk to himself, his fantasies posed a threat to me, too. But I also needed to find a way of financing the flight. Ezra wouldn’t press me for the money, but eventually the debt would have to be settled. And this time I couldn’t rely on Her Majesty’s Government to pick up the tab.

‘But,’ I said, pointing at the screen, ‘you only have twelve hundred coins.’ He grinned. And then it dawned on me. ‘Baaz … how many dollars are there to one of these Ethereum coins?’

‘Today, 1,389 dollars and 18 cents. Yesterday, 1,377 dollars and 72 cents.’ He closed the browser. ‘While we were sleeping, I made 14,044 dollars and 23 cents.’

‘What? But … twelve hundred and …’ I struggled with the multiplication.