Enigma by Robert Harris. This is a typical spy book with both codes and romance. It explores the life of Tom Jericho, a codebreaker from Bletchley Park. It is a good read and I found it rather interesting. It shows that the Park was made up of different "huts". Each hut was in control of a different part of the code breaking process and people in different huts could not even communicate with each other! The whole process was unbelievably secret and security was of the utmost importance. It is an interesting story with a well hidden twist in the tail.