When Agatha Christie wrote about a character named Major Bletchley in her 1941 novel N or M, most people didn’t give it a second thought. Of course, MI5 doesn’t qualify as “most people” and the name “Bletchley” was a bit too close for the comfort of the British intelligence services during World War II when everyone (at least everyone in the intelligence services) knew that Britain’s top code-breakers were holed up at Bletchley Park deciphering things. And one of those code-breakers was a gentleman named Dilly Knox, who just happened to be a friend of Christie’s.
The spooks became suspicious, according to Bletchley Park: The Code-breakers of Station X, a new book by Michael Smith. A recent article in The Guardian explains:
MI5 was anxious to find out what Christie knew... Knox said Christie could not possibly know what was going on at Bletchley, but agreed to ask her himself. He realised he had to be careful exactly what he said to the author. He invited her to his home at Courn’s Wood, Naphill in Buckinghamshire, and, according to friends of Knox, over tea and scones asked why she had named the Indian army major Bletchley.
Christie replied: “Bletchley? My dear, I was stuck there on my way by train from Oxford to London and took revenge by giving the name to one of my least lovable characters.” MI5 was relieved.
We consider that a likely story!