Or come together, depending on how you looked at it. There was, it turned out, a pattern in the carpet that Charles hadn’t spotted because he wasn’t looking. Even if he had looked, it would have seemed fanciful to perceive such an emerging shape. It was his failure, he had to admit afterwards; as chief of MI6 part of his job was to be alive to such possibilities but he had allowed familiarity and friendship, twin enemies of vigilance, to cloud his sight. Not to mention complacency and – harder to admit – age. The pattern was in the carpet all along but he did not see it until it was too late. Almost.

He later dated it to a precise moment at the reception, the first flickering indication that there might be a problem. The wide, red, wine-mottled face of a former colleague had grinned at him across a champagne glass and said, ‘Must say, retirement’s taught me what I long suspected.’ He paused for Charles to respond.

Charles struggled. He remembered the man – one or two of his postings and MI6 Head Office jobs, a minor scandal in New Delhi that led to divorce, his retirement party a couple of years before. Everything except his name.

‘That people have jobs to avoid work.’ The red face creased in laughter, the eyes almost disappearing in folds of flesh.

Avoidance of work was something else Charles now remembered about the man. He had done his quota of that in a so-so career limited not so much by lack of ability as by lack of aspiration and a preference for the diplomatic drinks circuit over the hard graft of finding and recruiting useful agents. One of those officers who was always in or between meetings, another way of avoiding work. But the name – Jerry something? John? There were so many Johns.

‘Of course, your own retirement must be coming up, isn’t it? Unless MI6 chiefs can prolong themselves indefinitely, which I doubt, these days. I suppose Gareth Horley will take over, will he? What he always wanted. Hungry Horley, we called him in Lagos. Always rushing off to the high commissioner with some titbit before telling his head of station. Usually a report that turned out to be exaggerated, putting it kindly. Mind you, with old What’s-His-Face as head of station – old Thingy, you know, that madman – can’t do names for the life of me these days – you couldn’t blame Gareth. Jimmy Milton, that’s it. Did you ever work with Jimmy? Mad as a hatter about security. Used to bury his house keys in his garden before going anywhere under alias. As if anyone claiming to live a blameless ordinary life in 123 Acacia Avenue wouldn’t have the means for getting back into 123 Acacia Avenue when he got home. I remember one day when Jimmy . . .’