He nodded, recognizing the description. There were five divisions within MI6 at that time, each with a departmental head. Diamonds, Hearts, Spades, Clubs and Jokers. The Clubs were overseen by a broad-backed, mastiff-jawed monster of a man. Quarrie Cochran-Nab. Scottish, but public school beat the accent and the trade unionism out of him. Distinguished himself with some quietly efficient successes in Poznan, Krakow and Sofia before being called home to take charge of the areas that his opposite numbers found too beastly for their taste. He’d done it well. He’d twice been in the running to take the hot seat: to answer to the name of ‘C’ and sign his paperwork in green ink. Twice, regrettably, he’d been deemed to be too blunt an object for the role. So he lingered on as an increasingly irascible Ace of Clubs while younger, more diplomatic career politicians joined him at the top table then departed for the House of Commons, the diplomatic corps or private sector consultancy positions. He was feared and adored in equal measure by the rest of the Clubs. His division did the counter-intelligence work; the rooting out of bad apples within our own barrel. When somebody was in trouble, it was the Clubs who did the deep-dive intelligence work and trawled through every last scrap of their life looking for evidence of traitorous leanings. They did the surveillance, the black-bag jobs; snatching up suspected traitors from the streets and seeing what it would take to buy them or break them. They were hard men. Hard women. Ex-soldiers, mostly. They’d been the unit that gave Walt a proper going-over in those unpleasant weeks and months when he was suspected of collaboration.

‘Play the next bit,’ said my companion.

I did as instructed. After a couple of seconds of silence the recording crackled back into life. I heard myself again. Walt was too far away to be picked up on the recording but I knew at once that it had been made while I stood and shivered in the crypt.