Throughout the book I was wondering whether it was based on a true story. Google has let me know that the book is 'semi-autobiographical'; the upcoming movie, not.
The world of spies has always been fascinating. A golden thread throughout is Dr Zhivago by Boris Pasternak, which is a movie / book that I would now like read too.
People who read the physical book (The Secrets we Kept) said it was brilliant, for me, the audiobook albeit interesting and I enjoyed the different voices, was ok.