They blindfolded me soon after that, and about twenty minutes later I was bundled out of the car and marched down a steep stairway. The room was cold and there was a slightly dank smell. Pipes gurgled in the background. Someone took the blindfold off. The two soldiers turned on their heels and took up station outside the door; Smale pushed me inside.

It was a familiar scene, right down to the naked bulb hanging from a coat-hanger. Beneath it, three men were seated behind a large desk that looked as though it were made from a solid block of steel. Two of the men were no surprise: Farraday and Osborne. The man sitting between them gave me more food for thought: Sandy Montcrieff, the Mirror reporter I’d met at the Lagos Yacht Club, and whom I’d later seen with Smale at the clinic in Udi.

We were in the ‘rubber room’, a space reserved for the interrogation of suspected double agents and other such undesirables; I’d sat in on a couple of sessions here before, during the renewed round of vettings after Philby had made a run for it. This gave me an advantage, of course. The bulb was burning through my eyes, but I knew it was a trick: it had been especially made by a company in Vauxhall to burn that bright, and the things were a devil to get replaced. Apart from the lamp, desk, chairs and a plastic bucket filled with dirty-looking water on the floor, the room was unfurnished, so as to enhance the subject’s isolation and disorientation - but I knew that we were in the soundproofed basement of one of the smarter hotels in West Kensington.

Despite all of this, I was much more afraid than the poor souls I’d seen interviewed here before. Because I was guilty.

Osborne asked me to take a seat, which I did. The chair was cold and too low. I mentally stripped the three of them, visualizing Montcrieff’s pale and bony legs, Osborne with his gut hanging over his belt and Farraday with unsightly moles across his back. It didn’t help much.

‘What’s this about?’ I said, selecting a tone somewhere between irritation and puzzlement. Might as well kick off proceedings. ‘Are you holding me responsible for Wilson’s death? I did everything I—’

‘I’m sure you did,’ said Montcrieff. ‘Thankfully, it wasn’t enough. But that’s just between ourselves. If you don’t tell us what we want to know, we’ll announce that you were the assassin.’

The other two didn’t flinch.

Montcrieff adjusted his cuffs and smiled innocently. ‘What we want to know,’ he went on, ‘is how long you thought you could get away with playing us all for fools.’

‘“Us”?’ I said. ‘Sorry, who the fuck are you again?’ I turned to Osborne: ‘William, I thought this was Service business.’