Aw thanks for your encouragement even without knowing the fandom! Bletchley Circle is a tv-show - a 2 series/seven episode wonder! (although, maybe you meant, read the fic for it?) Anyway it is kinda about codebreaking - it's about 4 women who used to work at Bletchley Park in the war and now they lead much more boring lives post-war so they get back together to solve a murder that the police are doing bugger all about. It's truly fantastic.

I am downloading Cryptonomicon to my kindle now. Exciting! I am Bletchley Park-mad. I went up to visit a few months ago and it was lovely and some of the women who used to work there give tours and demonstrate the machines - very cool!