He struggled to keep his breath even and shallow enough not to add more pain to his side. He finally slowed down as he cut through the grim, narrow Ham Yard to Archer Street, and was walking at a normal pace by the time he turned north into Rupert Street. Instead of continuing on the short distance to Kemp House, he turned right into Tisbury Court and stopped outside a small, anonymous door halfway down the alley. He didn’t want to risk going home yet, just in case the men from Trafalgar Square knew where he lived and had got there ahead of him. He needed somewhere to hide and recover, somewhere people wouldn’t think to look because they had no idea it existed.

He knocked on the door three times and after a long, pregnant moment, it opened.

The basement bar was dark, lit only by a few scattered candles. There was no way of telling how far back the room stretched, how many tables there were, or who was sitting at them. The only clues were the murmur of intimate conversations that mingled with the quiet, mournful jazz that played from somewhere, and the occasional candlelit glint of a cocktail glass or flare of a burning cigarette.

The bar was private, members-only in all but dues. It served a clientele who didn’t want to be seen, who craved respite from the city above and wanted to be alone, or sometimes together, away from prying eyes.

It would normally take a few minutes to adjust to the dimness, but Knox had been to this particular clandestine refuge from the world enough times to know his way through it with his eyes closed. He walked in a diagonal across the room, avoiding the tables and legs of the other patrons, to a long counter lined with stools and a row of low lamps.

A man sat at one end of the counter. His body was lost in the dark but his tanned face and perfectly quiffed hair were haloed by the lamp hanging just above them. Knox chose a spot at the other end, suddenly conscious of how much of a mess he must look after his sprint across Soho. He slouched on his stool, craning his body to avoid the pool of light on the counter in front of him, and nodded to the bartender, a woman in a three-piece suit whose pompadour hair matched the man’s.

‘You look like you’ve had a time of it,’ she said. ‘What’ll it be? Vodka? Whisky?’

‘Both,’ Knox answered.

‘Sure thing.’ She poured two generous measures of the spirits over ice and passed the two glasses across the bar to Knox.