A spy, like a writer, lives outside the mainstream population. He steals his experience through bribes and reconstructs it.

But I think the real tension lies in the relationship between what you might call the pursuer and his quarry, whether it's the writer or the spy.

The spy who came in from the cold.

It's part of a writer's profession, as it's part of a spy's profession, to prey on the community to which he's attached, to take away information - often in secret - and to translate that into intelligence for his masters, whether it's his readership or his spy masters. And I think that both professions are perhaps rather lonely.

Every writer knows he is spurious; every fiction writer would rather be credible than authentic.

'The Spy Who Came in from the Cold' was the work of a wayward imagination brought to the end of its tether by political disgust and personal confusion.