Konstantin Volkov had walked into the British Consulate-General in Istanbul in 1945 and asked to defect. He’d had information that would have blown Philby, but Philby had wangled his way into getting the job to fly out to interrogate him, and he’d taken enough time doing it for his handler to send some goons in to take the Russian and his wife back to Moscow. This was now known, thanks in part to Philby himself, who had published a slippery little volume of memoirs revealing just enough to push my colleagues into further paroxysms of paranoia. If Slavin suddenly disappeared, it would be clear he had been silenced by the double, and as the only men who knew about Slavin’s allegations were Lagos Station and Heads of Section, that would narrow the field considerably. I had to get out to Nigeria as soon as possible, because I couldn’t run the risk of someone else interrogating Slavin before me. But if anything happened to him, either while I was there or on my way out there, it would narrow the field to just one.

‘You’re safe,’ said Sasha. ‘Didn’t you come through with flying colours last time? Nobody would ever seriously suspect you.’ He patted the leather upholstery pointedly. ‘Your cover is impeccable.’

‘You’re making me blush,’ I said. ‘But my last experience of being questioned was notably different, I think, don’t you? I hadn’t, for example, just killed the Head of the Service. If Slavin is mysteriously shipped off in bandages moments before I arrive in Lagos, I’ll either spend the rest of my life in Pentonville or end up dangling from the end of a rope.’

‘Let us be perfectly clear, Paul. What is it you are asking of me?’

‘Keep your thugs away. Let me deal with Slavin.’

He took a sharp intake of breath, and gave a quick shake of his head. ‘It is far too dangerous.’

‘Reassuring to hear that you care, but I’ll be the judge of that.’

‘It’s impossible.’

‘It’s non-negotiable.’

He gave me a long look. ‘They won’t let me.’

‘Then don’t tell them.’ I leaned a little on the last word - his incessant passing of the buck was beginning to irritate me.

‘I can’t do that. There is another option, you know—’

I gave him a cool look. ‘The flat in Moscow? Pissing away the rest of my life on cheap vodka like Philby and the others? No thanks.’

‘I’m afraid I can’t help you. I wish I could, I really do, but it’s not in my power—’

I took the next corner, up a ramp to a space in front of someone’s lock-up, ‘Millwall FC’ scrawled across it in blue spray paint. I pulled the brake and drew the Luger, then faced my comrade down the barrel.

He’d shut up now.