Joan Clarke to Alan Turing - 'Do you know, this morning I was on a train that went through a city that wouldn't exist if it wasn't for you. I bought a ticket from a man who would likely be dead if it wasn't for you. I read up, on my work, a whole field of scientific inquiry that only exists because of you. Now, if you wish you could have been normal. I can promise you I do not. The world is an infinitely better place precisely because you weren't.'
