I woke, sweating hard, at 5.30 a.m. There had been no more messages from whoever was using Mescaline’s protocols. I checked world news, then found shorts and a T-shirt, ran hard across Hyde Park, outpacing the night’s images, one eye out for any surveillance. A mile and a half in eleven minutes. Not bad: would get me into infantry, but not paras any more. I drank a bitter coffee at a cab drivers’ shelter, the only place open in the dawn. I had been looking forward to today. To a tentative attempt at being myself.

At 9.30 a.m. I walked to the Maghreb Bookshop on Sussex Gardens, behind the Edgware Road. It was a cornucopia of second-hand books from around the world, most languages represented, forgotten poets gathered in the dust, shelves that squeezed you as you burrowed in.

After half an hour, I took my haul to the counter and the owner studied them. Among others, I had chosen some poetry in Kalmyk – the Kalmyks in Russia were Buddhist descendants of the Mongols – plus a nineteenth-century account of travelling in Kazakhstan. The owner was a small Egyptian man who wore V-neck sweaters and glasses on a chain. He lifted the Kalmyk collection.

‘You understand this?’

‘A little. I am interested in endangered languages.’

I pocketed the Kalmyk collection and the Kazakh travelogue, took the rest to a house on Lisson Grove. It was identical to the elegant houses on either side but for a small brass plaque beside the door announcing the Healing Foundation for the Victims of Torture. The door was open. I walked into a long hallway with clients’ artwork on the walls, leading directly through to a well-tended garden, where a Sudanese couple were arranging bunting and tables for a party.

‘Is Hany around?’

At the sound of my voice, Hany Aziz appeared, grinning, from among the foliage.

‘Martin,’ he said, because Martin was the name he knew. He clasped my hand. I savoured the sweet incongruity I felt every time I saw him in London, a man I had first set eyes on in Cairo’s Tora Prison. That crippled figure had been banished. Aziz’s tightly curled hair was now a London grey, but his eyes had grown more youthful. A fine access agent, once I’d acquired his freedom and services, introducing me to the intellectuals and firebrands that passed through his basement. He had established the healing centre five years ago, after arriving in the UK.

I gave him the books and we asked after one another’s lives. He told me how he was faring; I lied about mine.

‘You must come to the party this afternoon, Martin. Old friends will be there. You remember Sania.’

‘Of course.’

‘They remember you fondly. And the children.’

‘Not today.’

‘Then next time.’

‘I promise.’