The fifth file was slim. The only overseas call made from the Dubai number – no transcript provided – was to a satellite phone in southern Lebanon.

The sixth file, again a single sheet of flimsy paper and again no transcript, recorded a call from the satellite phone located inland from the city of Sidon to a number in Prague, capital of the Czech Republic.

The seventh file, courtesy of the BIS in the city, identified a message received in Prague on a number that was tapped. The transcript was one line: 'Gift received. Love, gratitude and always my prayers.' The number in Prague to which the message had been sent was monitored because it was used by an Albanian national, believed involved in the organized-crime racket of moving Romanian, Ukrainian and Bulgarian girls to northern Europe for prostitution. The warmth of his smile spread because Wilco's signature was on the cover note.

In front of him now, brought to him by his faithful PA – and he'd have sworn she had the same caring eyes as her spaniel – was Wilco's latest message. The Albanian was a cafe owner and prosperous. Records showed he also owned a third-floor apartment in the Old Quarter of Prague, and the unpronounceable name of a street was listed. He began to wolf his sandwich, gulping it down, then swilling his mouth with the water. 'Satisfied?'

'It's only you I'm thinking of, Mr Gaunt.'

She could have called him Frederick or Freddie – she had been with the Service for twenty years, fifteen of them running his desk at home and abroad – but she was never familiar. Without her, his professional life as a senior intelligence officer would have been so much the poorer. He said, 'I'm going off to see the ADD, dear Gilbert, to tell him I want to run with this.

Meantime, message Wilco that I'm controlling it, and all signals come to me, please.'

He was up and scraping sandwich detritus from his shirt, then buttoning his waistcoat, reaching for his suit jacket from the hanger.