"Did you know him?" a priest asked me when I first visited my father's impressive marble tomb in Bosnia.
I gave an honest answer - "No, I can't say I really knew him at all".
It was a view shared by the former head of the Secret Intelligence Service's anti-Soviet operations.

"I don't suppose we'll ever really know the truth about J.B. Wood?" he told me. But he thought I had a better chance of finding out than most.

After all, most of my family had at one time or another been with SIS, my mother one of only a handful of female agents to have operated behind the lines in post-war Berlin.

I had grown up within the perimeter of a specialist SIS training camp, surrounded by some of the most senior - and colourful - characters in the Service's history.

So began a personal, insider's investigation into the life - or lives - of one of SIS's more unlikely, if highly regarded, officers. And, in an admittedly crowded field, one of its most duplicitous.