by Leo Marks
The incentives for the German to reply to it were very great indeed (and will be dealt with under ‘possible German reactions’).
But there was one imponderable factor which was more important than any of these. What if Boni were not in enemy hands?
However remote the possibility, it had to be catered for.
Special Precautions
If Boni were free but couldn’t decode his instructions an entire operation could be jeopardised.
But if Boni couldn’t decipher a message that he wasn’t supposed to receive anyway because its contents were obsolete, no harm would have been done to him apart from the tedium of trying to decode it. That was why I’d delayed Plan Giskes until the Dutch cancelled a message to the field.
And if he made the mistake of replying to it, he’d tell us what we needed to know.
Method of Encoding
Boni’s poem was:
I sometimes wish
I was a fish
A-swimming in the sea
A starling on a chimney pot
A blackbird on a tree
Or anyone but me.
I chose five words and numbered the letters sequentially, wishing I had the dexterity of the Grendon coders:
T
R
E
E
C
H
I
M
N
E
Y
F
I
S
H
W
A
S
S
E
A
19.
15.
4.
5.
3.
9.
11.
13.
14.
6.
21.
8.
12.
16.
10.
20.
1.
17.
18.
7.
2.
I began by encoding the message in the normal way but deliberately misspelt several words of the text to give the impression it was the work of a tired and careless coder.
Then came the point of no return. I transposed two columns in the wrong order – a favourite pastime of Peter Churchill’s (known in the trade as ‘hatting’).
The effect of ‘hatting’ was to throw the letters out of alignment so that some of the clear-text would read normally, and the rest (to the untrained eye) would be gibberish. A cryptographer could tell at a glance what had happened and would calculate how to ‘unhat’ the columns to bring the letters into proper alignment – a process which would tax his patience more than his mathematics. But agents like Peter Churchill also ‘hatted’ columns in the second transposition.
A double dose of ‘hatting’ would be an altogether different matter. It would throw the letters much further out of alignment and make the cryptographer’s task at least twice as onerous. This posed a (to me) unanswerable problem:
Swamped by important military traffic, how much time could the Germans devote to unravelling dropped stitches in an agent’s message? What priority did they give to SOE’s traffic?
These were the questions I’d wanted to ask Tiltman. Without his guidance, I took no chances on the Germans being overloaded and encoded the second transposition normally. It was essential that they didn’t take long to unravel ‘London’s mistake’, but possession of Boni’s poem would cut the time by half, and after a few Gott im Himmels they’d be certain to spot some key words amongst the surrounding gibberish:
FLORINS would appear as FLOR with INS in the line beneath it.
THOUSAND would appear as tho with usa and nd in the same line.
MESSAGE (a word which all cryptographers looked for) would appear as MGE with ESSA in the line above it.
A few nudges later and the rest of the message would fall into place for them.
Problem Areas
At this late stage the only one worth a final ponder was Giskes’s reactions to an indecipherable from London.
He’d pretended that two of our messages to Potato were indecipherable. When confronted by a genuine one, why wouldn’t he tell us that it was indecipherable instead of attempting to reply to it?
Because he was playing for time with Potato. But time was against him now. With a dropping operation one night away – with agents, florins, containers, the lot, about to descend on him – why should he risk causing even a few hours’ delay by asking London to repeat a message when he already knew its contents?
I was convinced that we had everything to gain and nothing to lose by trying to catch Giskes in an off moment.
It was time to find out.
Praying that Bingham wouldn’t suddenly appear, I handed message number 60 to the Signals Office supervisor, and told her that I’d encoded it myself to save time. I then instructed her to teleprint it to Grendon with top priority in time for Boni’s next sked.
As I hurried back to my office, my spine began tingling. Why did I have a feeling in the mind of my back that somewhere in all this I’d made a mistake?
It wasn’t until I received a panic-stricken call from the supervisor of the Grendon night shift that I realised what was wrong.
The coders had discovered that the message to Boni was indecipherable. Knowing that I’d encoded it, they hadn’t checked it until it had already been transmitted. I’d forgotten my standing instruction that all messages to the field must be double-checked and initialled by the supervisor.
I assured her that no harm had been done because message 60 had just been cancelled, and its replacement would be sent on Boni’s next sked.
She asked if she should notify the Dutch section, which was the last thing I wanted, and I undertook to contact N section immediately and accept full responsibility.
An idea then occurred for turning the mistake to advantage, a prerequisite for survival in SOE. If I could tell the sceptics in SOE that a squad of coders had made a blanket attack on the indecipherable and failed to break it, they could hardly maintain (as some undoubtedly would) that Boni could have decoded it himself.
I informed the remorseful supervisor that I’d carefully checked my encoding and thought the mistake was in the teleprinting. To prevent this happening again I’d like the night squad to do their best to break it so that we could determine whose fault it was. I added that I was very anxious to know the result and that if the girls hadn’t broken it by the time I left the office, I’d be grateful if she’d telephone me at home, no matter how late it was.
She promised that the night squad would start a blanket attack at once.
I waited another hour and then went home.
Boni stretched out a hand which had only one finger on it and screamed into my face, ‘What have you done to me, what have you done to me?’
It was Mother trying to awaken me at six in the morning. She’d had a message from some girl whom she’d refused to put through to me. The message was to tell Mr Leo Marks that she and her friends couldn’t do it.
Mother demanded to know what it was that she and her friends couldn’t do that I had to be told about at six in the morning.
‘Their duty,’ I said.
Boni was still screaming when I tried to do justice to her blackmarket breakfast.
TWENTY-THREE
Special Devices
On the morning of 16 February there was a sound rarely heard in the code department – a sigh of relief – when a car called to take me to the Thatched Barn at Barnet. I’d forgotten that I was to spend the whole day with its commanding officer, Colonel Elder Wills.
Boni’s next sked would be over by the time I returned.
The Thatched Barn was a famous inn on the Barnet bypass which Wills had skilfully converted into a camouflage and special-devices station. The gifted colonel had offered me a conducted tour of his bizarre establishment not because he wanted to meet me but because he’d
been offered a contra-account he couldn’t resist: a conducted tour by Nick of an equally inaccessible workshop, the wireless station at Grendon.
It was my job to persuade him to give absolute priority to the camouflaging of WOKs.
I stood at a respectful distance as he proudly displayed a huge assortment of horse manure, camel dung and mule, cow and elephant droppings, which had been delivered to him by the London Zoo at the personal request of Sir Charles Hambro.
It was a huge dollop of merde alors for Wills that Hambro was not only a friend of Churchill’s, and the youngest director yet appointed by the Bank of England, and a former chairman of Great Western Railways, but was also a fellow of the Royal Zoological Society, and it was in this capacity that he’d persuaded the head of the zoo that his waste product could make a valuable contribution to the war effort.
I thought at first that this exotic collection of excreta was a present for C, but he gleefully explained that it was in the process of being reproduced in plastic, and would then be hand-painted and filled with explosives. The horse manure was destined for western and northern Europe, the camel dung for North Africa and the mule, cow and elephant droppings for the Far East. Once trodden on or driven over (hopefully by the enemy) the whole lot would go off with a series of explosions even more violent than the ones which had produced it.
Amongst Wills’s more civilised creations were milk bottles which exploded when the caps were removed, fountain pens guaranteed to write off whoever unscrewed them and loaves of bread it would be unwise to regard as the staff of life. He had a stock of cigarettes guaranteed to cure people of smoking as they were packed with incendiary and explosive materials, and they’d done no good at all to German stores, fuel tanks and armament dumps in France, Belgium, Holland and Norway. He also had on offer a variety of nuts and bolts which had been hollowed out and filled with explosives; these he warmly recommended for railway engines and shunting yards.
Since agents often hid their WT sets in lavatory cisterns, he’d devised a lavatory chain which could act as an aerial. He also had a stock of lethal toilet paper, which he hadn’t yet issued because he couldn’t be sure it would be used by the right behinds.
He took me into a shed, which was packed with innocuous-looking suitcases specially made for carrying WT sets. Each suitcase had been artificially aged and designed to fit into the territory in which it would be used. Every suitcase was equipped with secret compartments and a false bottom.
Agents’ clothing was the only problem which had come close to defeating him. He had to reproduce continental tailoring and stitching, which was very distinctive and varied greatly from territory to territory. He’d finally recruited a Jewish tailor, a refugee from Austria, who’d visited synagogues all round the country to borrow old clothes and labels from his fellow refugees. These labels were reproduced in Wills’s workshop and sewn into the clothes, which the tailor had copied and which Wills had carefully aged. Boots and shoes (also carefully aged) were provided by a firm in Northampton, and Wills added sliding heels to them to provide cavities for microfilms and other small objects. In fact, everything in sight was ‘suitably aged’ but me.
I found myself thinking about the ageing process, an undignified business which both sides in the war were doing their best to spare us:
When your words
Become distant relatives
Who seldom visit you
When all dates are one
And all times the same
And what you put down
You can no longer pick up
Remember that you
Now helpless
Who used to be a fighter
Make fools
Feel brighter.
Another one for the ditty-box perhaps?*
Keeping the best till the last like the supersalesman that he was, Wills took me into the ‘special documents’ department where most of the forgeries were done, and showed me what he’d provided for the Golf team.
They were to be issued with forged Dutch, Belgian and French identity cards, frontier passes, dyes for forging German passes, rubber stamps with swastikas on them, and everything else that would be needed to guide Jambroes through France and Belgium to the Spanish escape line. Some of the printing had been done by Professor Newitt of the Imperial College of Science, where Wills had his own office. He also had the use of a workshop in the Natural History Museum – where Julian Huxley was his technical adviser on urgent problems such as the reproduction of excreta.
Glancing at his watch, which concealed God knows what, he finally asked what he could do for the agents’ code department.
I had to be careful how I answered him. I’d been warned by Joan Dodd, who knew him well, that he had a propensity for taking instant dislikes to people and that his receptivity was an excellent example of his own camouflage. She’d also told me that he used to be an art director at Elstree Studios, that he’d graduated to making films (including Song of Freedom with Paul Robeson) and that his present production at the Thatched Barn was running well over budget. To get the best out of Wills, he had to be confronted by a major challenge, and there weren’t many which were new to him.
Wishing I could sing like Paul Robeson, I began the Song of the WOK by stressing that agents would resist carrying them because of the number of random street searches. The decisive factor would be the quality of the camouflage.
Clearly disappointed that he couldn’t see a problem, he said that silk codes could easily be camouflaged in toothpaste tubes with special compartments, in shoelaces with soft tubes inside and in an infinite number of conventional objects, which would certainly stand up to random street searches and might even be safe under close examination.
Having disposed of the WOK problem, he picked up two lumps of coal which were packed with high explosives and began to describe their glowing future. WOKs were obviously just another job to him.
Determined to raise their status, I shot some questions at him: Could code keys be invisibly printed? – on handkerchiefs perhaps? How could agents read them? – and when they’d used them, how could they erase them? They couldn’t cut them away and walk around with their handkerchiefs in tatters!
In his excitement he dropped both lumps of coal, and I said goodbye to my parents.
But they must have been defective (the coals, not my parents) because the only explosion came from Wills himself: ‘Y-e-s! – we can do it.’
Of course it was practical for WOKs to be invisibly printed! And of course the agents could read them. He’d invented a new invisible ink which could be detected only when exposed to infrared lighting. All the agent needed to do was switch on a torch with infrared discs inside it and he could read the WOK keys without difficulty. Nor did the torches need to be camouflaged. Everyone in occupied Europe carried one to cope with the blackout.
My suggestion about handkerchiefs was good but there were other possibilities. WOKs could be invisibly printed on men’s shirt tails and pants and on women’s knickers and petticoats. As for erasing each key chemically, it was a fascinating problem and would have his immediate attention.
The Tiltman of camouflage now galvanised everyone within earshot at his Barnet Bletchley. WOKs could be microfilmed and carried in tiny containers which could be hidden in various parts of the body such as the navel or rectum. A matchstick could accommodate two hundred WOK keys. It would be hidden in an ordinary box of matches and the agent could identify it by a tiny indentation which only he knew about. As for reading the microfilm, he was working on a small powerful microscope with detachable parts which could easily be assembled and which would be no problem to camouflage.
He then began a long technical discussion with his assistants, many of whom he’d recruited from Elstree Studios.
They rapidly lost me. Nor was I any longer necessary. I was a little disturbed about codes being concealed in the rectum and intended to be missing when the coders of Grendon announced: ‘We have received our first indecipherable due to
anal interference beyond the agent’s control.’
But everything else I’d heard and seen had removed my last anxiety about the future of silk codes. If Wills could devise a lavatory chain which acted as an aerial, he was capable of camouflaging anything. He might even be able to return me to Baker Street camouflaged as an adult.
I decided to leave before he had the chance.
Note
* Subsequently included in a batch of micro-filmed poems sent to Jugoslavia.
TWENTY-FOUR
Judgement Day
There were only three things which SOE’s agents could anticipate with confidence. That their parachutes would open, that their L-tablets would kill them and that their messages from London would be accurately encoded.
The Signals directorate could be sure of only one thing. That any WT operator who received a message which he couldn’t decipher would ask the Home Station to ‘check and repeat’ it at his next sked. This elementary procedure was a fundamental act of self-preservation and as reflex to an operator of Boni’s calibre as switching on his set.
His indecipherable had been transmitted to him on 15 February, and he’d acknowledged receipt of it by sending AK/R in Morse. He’d also acknowledged receipt of Bingham’s new number 60, which amplified several parts of his (as he believed) cancelled text.
That was twenty-four hours ago, and from his next sked onwards it was essential to play the devil’s (Giskes’s) advocate and assume that Boni was free until his responses proved otherwise.
On 16 February London and Boni exchanged messages. London’s message (number 16) informed Boni of a change of plan. The money he’d asked for would not be delivered to him by the Golf team but by the two other agents (Tennis and Hockey), who were waiting to be dropped. The message confirmed that a stores operation would take place that night.
