A Spy Named Orphan by Roland Philipps

Donald Maclean was a star diplomat an establishment insider and a keeper of some of the Wests greatest secrets. He was also a Russian spy... Codenamed Orphan by his Russian recruiter Maclean was Britains most gifted traitor. But as he leaked huge amounts of topsecret intelligence an international codebreaking operation was rapidly closing in on him. Moments before he was unmasked Maclean escaped to Moscow. Drawing on a wealth of previously classified material A Spy Named Orphan now tells this Paperback softback