1. London, Late May 2011.

"Christ, Hal, now you've really got me worried," I thought as I watched my old friend stride away through the silver-bright rain. "What the Hell was that about?" We had known each other for over 30 years at this point, through the incredible highs and lows of both the job and our personal lives and had seen each other in almost every mood imaginable but I had never, ever seen, or thought I would see, Harry Pearce driven by what seemed to be a mix of panic and paranoia. As for his ultimatum, well I'd be lying if I said I wasn't chilled to the core. I've seen him pull that act before, plenty of times, but hadn't been on the receiving end. Now I realised why it had always been so effective: it wasn't an act. We each know perfectly well exactly what the other is capable of and I knew, in that instant, that he really would take on not only me personally but my entire organisation. In his current mood, we would be the ones who would come off second-best.

I'd had a bad feeling in my bones about all of this ever since the name Elena Gavrik had come out during our conversation in the pub that day and now it looked as though I'd been right. She always had been bad news and I hadn't expected this time to be any different but I also hadn't expected her to be able to have this this much of an effect on Harry after so long – it had been a quarter of a century, for Christ's sake. That she was behind what was going on I had no doubt but I was really going to have to go through all those files again, today, to see if I could work out why, although I was starting to have a fairly strong inkling about that.

What had hurt the most, though, was the direct, unequivocal accusation that I had been behind the death of his young techie. I could shrug off the inference that I had something to do with the failed hits on the Gavriks – if positions were reversed I would be thinking the same thing about him – but that he would even consider that I would take the life of one of his crew was devastating and spoke volumes for how twisted his thinking had become.

As I watched his figure dwindle and disappear through the pillared portico at the far end of the courtyard I thought about how tightly he seemed to be wound up – so tightly he was about to snap – and that was a prospect I viewed extremely bleakly. There weren't too many of us old-timers left active in the Service, with most of our compatriots either retired, long-since escaped to real life, gone crazy or, too often, dead. As a result, those of us remaining tended to think we were immune to everything, being both bullet-proof and unbreakable, and Harry had always been one of the most unbreakable of all. And, speaking of breaking, seeing him in his present state was doing exactly that to my damned heart – the one my two ex's say I don't have – and I really didn't want to have to watch what was coming but it looked like I'd left it too late to avoid. That he, of all people – Jesus, we'd been as close as brothers at times in Berlin and the affection had remained ever since – seemed to be on that irreversible down-hill ride to God-know what was devastating. Maybe I'd been stupid to think we might both actually make it, reasonably unscathed, to an honourable retirement…

For me, of course, it had all begun with that telephone call from the boss.