As the Second World War approached, Tolkien was asked whether he would be prepared to serve in the cryptographic department of the Foreign Office in the event of a national emergency - analysing encrypted messages and obtaining valuable military intelligence at Bletchley Park - a similar duty seen in this year's movie "The Imitation Game" with Benedict Cumberbatch. He agreed, taking a course at the Government Code and Cypher School in March 1939; though wasn't required at the time. It's said that Tolkien later turned down a £500-a-year offer to become a full time recruit, although no one knows why.
