I have a soft spot for a good mystery.  My first three books ­ A Stranger in my Street, Taking a Chance and A Time of Secrets were all ‘whodunnits’ set in WW2.

Which is why I was delighted to attend the inaugural Capital Crime Writing Festival in London last week.

The first session I went
to was “The Influence of Agatha Christie”. Like many
authors, I remember reading an Agatha Christie as my first ‘grown-up’ book.

Bletchley Park House

Listening
to the panel reminded me of a time in WWII when the Queen of Crime was
suspected of using one of her books to send coded messages to the Nazis.

It relates to the codebreakers at Bletchley Park near Milton Keynes, which is one of my favourite museums.

During WWII a small
group of code breakers at Bletchley Park developed techniques for decrypting
messages coded using electrical cipher machines that the Germans considered
‘unbreakable’. The flood of high-grade military intelligence deciphered by
Bletchley Park was code-named Ultra.

Colossus machine

The messages included information about German spies in the UK, which
led to the capture of every German spy in the country. Most became
double agents under the British Double-Cross Operation and were used to
disseminate false intelligence to the Abwehr (German Military Intelligence).

It is estimated that the codebreakers at Bletchley Park shortened the
war in the Atlantic, the Mediterranean and Europe by between 2 and 4 years and may even have altered
its outcome.

It was crucial that the enemy remained wholly
unaware of the work being done at Bletchley Park. 

Agatha Christie – Queen of Crime

At the same time that the Bletchley Park
codebreakers rushed to break the German Enigma code, Agatha Christie was
writing her first spy thriller.

In N or M, which was published in 1941, the daring
detective pair, Tommy and Tuppence Beresford, are recruited by British Military
Intelligence to discover the identity of a German spy. An important character in
the book is Major Bletchley, an annoying retired Indian army
major, who professes to have inside knowledge of the war. 

Like all Christie’s books it was a best-seller, but it caused consternation
in MI5. Was Christie sending a message in the novel, letting the enemy know
that not just the fictional Tommy and Tuppence, but also MI5 were unmasking
German agents? Was she divulging that “Bletchley” was significant in this?

Or was it all just a strange coincidence?

Agatha Christie was ‘the Queen of Crime’. If MI5 agents or the police went
to interrogate Christie about her choice of character name, it might bring
damaging publicity.

MI5’s Chief Cryptographer at Bletchley Park was
Alfred Dillwyn “Dilly” Knox, who was a close friend of Agatha
Christie. MI5 had a word with him about it. Although he considered it
laughable that Christie knew anything at all about what was going on at Bletchley
Park, he agreed to talk to her. 

He did so in a very British manner. Over tea and scones at his home in
Buckinghamshire, Knox asked Christie in a light-hearted manner how she arrived
at the names of the characters in her books. Major Bletchley, for instance, in
her latest novel.

Bletchley Station

Christie gave an innocent explanation. She had been stuck at Bletchley Railway Station, on her way by train from Oxford to London. Annoyed at the long delay, she took revenge by giving the name Bletchley to one of her least loveable characters.

Knox reported back to MI5, who were apparently reassured by this
explanation.

And yet…

In the 1940s the route of the (now defunct) “Varsity Line”
between Oxford and Cambridge went through Bletchley. But Christie said she was
on her way to London. Why would she go to Bletchley when there was a direct
Oxford-London line she could have taken?

She may have had no choice. German bombings meant the UK railway service
was in a parlous state at that time. Diversions and long delays for
non-military transport were common and very irksome to travellers. Christie’s
explanation for using “Bletchley” may be the simple truth.

But there is another, very interesting facet to the story.  During the Second World War, and when she was
writing N or M, Christie lived at the Isokon building in Hampstead, an
avant-garde 1930s apartment building.

Isoken Building

I have visited the Isokon, in which reinforced concrete was used in
British domestic architecture for the first time. It was designed for
well-heeled tenants who wanted a minimalist lifestyle with few possessions and who
didn’t like cooking. The apartments had no kitchen, but food could be ordered
from a general kitchen on the ground floor.

The tenants it attracted included around twenty-five Soviet Russian spies,
who lived there between the mid-1930s and mid-1940s.

In fact, one of Christie’s neighbours was Arnold Deutsch, the controller
of the infamous spy group of Kim Philby, Guy Burgess, Donald McLean and Anthony
Blunt.

The Isokon is not a large building and Christie must have known her
neighbours. Was it co-incidence that while living there, she first tried her
hand at a spy novel? Or did Christie overhear something in the Isokon
that provided the seed for her spy story? 

Was it coincidence that she should give a character in that novel the
name of the top-secret establishment where British codebreakers led by her
close friend were deciphering Nazi messages, including those relating to German
spies in Britain? Had Dilly Knox himself innocently mentioned
Bletchley Park in Christie’s hearing? Or was the railway station story the
truth. Or was it a mixture of the two?

J.R.R Tolkien is quoted as saying that a story:

grows like a seed in the dark out of the leaf-mould of mind: out of all that has been seen or thought or read, that has long ago been forgotten, descending into the deeps.

J.R.R. Tolkien

I’m sure Christie herself had no idea how, but the name “Bletchley”
allied to the idea of German spies slipped into the leaf-mould of Agatha
Christie’s mind and took root there.