Writing is like walking in a deserted street. Out of the dust in the street you make a mud pie.

Once you've lived the inside-out world of espionage, you never shed it. It's a mentality, a double standard of existence.

I began writing when I was still in the British Foreign Service, and it was then understood that even if you wrote about butterfly collecting, you used another name.

You have no idea how humiliating it was, as a boy, to suddenly have all your clothes, your toys, snatched by the bailiff. I mean we were a middle-class family, it's not as if it was happening up and down the street. It made me ashamed, I felt dirty.

It is my writing dilemma. The world of spying is my genre. My struggle is to demystify, to de-romanticise the spook world, but at the same time harness it as a good story.

I am still making order out of chaos by reinvention.