Between Silk and Cyanide

by Leo Marks

  It was time to go in.

  EIGHTY-ONE

  The Last Mischief

  ‘Vengeance is mine,’ saith the Lord, and it soon became apparent to SOE’s expatriates that someone in C had read the Bible.

  None of us expected a civic reception, but we were quite unprepared for the torture which was about to be inflicted on us in the name of security.

  The moment we arrived at Curzon Street House we were incarcerated in the noxious bowels of a sub-basement where it was as difficult to breathe as to think and where we were visited once a day by a doctor, though he was himself asphyxiated by the end of his rounds.

  My assistant Liza Vaughan had a Turkish bath next to mine, and Ann Turner (who had sole charge of SOE’s WT records) had an office within choking distance. Heffer didn’t need one, as he only looked in twice a week ‘to see how things were going’, and promptly went with them. We rarely saw our country-section colleagues but could hear them coughing in the corridor, a reasonable indication that they were still alive.

  We were forced to accept that we’d walked out of the fire and into the frying pan, yet there was one compensation.

  The sub-basement we occupied had been used by the War Cabinet to protect them from the worst bombing, and at least twice a day I had the privilege of peeing into a toilet once used by Churchill. I put out my cigar on these occasions as its fumes would have spread throughout the building. Heffer, an expert in such matters, said that an earlymorning fart in Curzon Street House would be wafted back to its owner by the end of the day.

  In deference to his judgement I christened the new code ‘Windswept’. An astute colonel named Maltby (who was Gambier-Parry’s Heffer) often looked in to examine its progress and professed himself ‘delighted with it’. Which was more than I was.

  Although I was convinced by now that there would never be lasting peace as long as governments used codes, I’d devised one which would allow ambassadors to communicate their good intentions en clair whilst concealing their real ones with a little help from Windswept. Perhaps I’d finally learned the meaning of SOE-mindedness.

  On 12 February Heffer called in, though he’d already done his two days’ stint. ‘You might like to see this,’ he said.

  He held out a copy of the London Gazette and pointed to a brief announcement: ‘The King has been graciously pleased to award the George Cross to Acting Wing Commander Forest Frederick Yeo-Thomas, mc (89215), Royal Air Force Volunteer Reserve.’ (The French had their own way of saying ‘Merci, Tommee’. They subsequently named a street in Paris the ‘Rue Yeo-Thomas’.)

  I pinned the announcement to the wall to give the room its only natural light, and six weeks later Windswept was finished. Although I’d refused Gambier-Parry’s and Maltby’s offers to continue in C in whatever capacity suited me best, they’d allowed me the privilege of signing off in their Broadway HQ instead of the building at the top of St James’s Street, where the ritual normally took place.

  I noticed that the door of the code room was kept tightly closed throughout but Gambier-Parry and Maltby were there to shake hands, and Maltby saw me off the premises.

  My code war was over, and I stood in the fresh air with nowhere to go.

  Twenty minutes later I found myself in Baker Street.

  Montagu Mansions was in the hands of the agents, and had a to let sign outside it. There was no one in sight, and the front door was open.

  I entered my old office. It was even barer than I felt. The walls had been covered in off-white paint, which matched my complexion, and the room had been stripped by a demolition expert.

  It was impossible to believe that forty million code groups had passed through this nothing of a room, or that Tommy and Nick, Gubbins and Templar had once paced up and down it. Or that this was where I’d learned of the capture of Noor and Violette.

  Wondering whether the new agents would suffer as much as ours had and how we’d managed to learn so little from so much, I felt the sudden onset of a poem. Although I’d resolved not to write one in peacetime (poems had killed too many agents), it demanded the same rights of way as ‘The life that I have’.

  I had no paper but found a piece of chalk and wrote it on the wall where the silks had once stood:

  We listen round the clock

  For a code called peacetime

  But will it ever come

  And shall we know it when it does

  And break it once it’s here

  This code called peacetime?

  Or is its message such

  That it cannot be absorbed

  Unless its text is daubed

  In letters made of lives

  From an alphabet of death

  Each consonant a breath

  Expired before its time?

  Signalmaster, Signalmaster

  Whose Commandments were in clear

  Must you speak to us in code

  Once peacetime is here?

  I suddenly felt that someone was watching me, and turned round slowly hoping it was Ruth.

  A charlady was standing in a doorway with a mop in one hand, a bucket in the other and a cigarette dangling from her mouth. She looked at me suspiciously. ‘You from the agents?’ she asked.

  ‘Yes,’ I said, ‘I suppose I am …’

  She glared at the defacement on the wall.

  I tried to erase it but had no rubber and asked if I could borrow her mop, which she reluctantly surrendered.

  I took a last look round the room and closed my eyes while I said goodbye to it.

  ‘Lost something?’ she enquired.

  ‘Yes,’ I said, ‘I suppose I have …’

  And walked out of her office to make what I could of a code called peacetime.

  Epilogue

  Tommy died in 1972 without knowing that I was going to write this book, which doesn’t necessarily mean that he hasn’t read it, and there are certain facts he would expect me to disclose.

  Ninety per cent of the WT records handed over to C in 1946 have been destroyed, and the code department’s records scarcely exist. According to successive archivists (whose assurances I accept), ‘intensive efforts’ have been made to find my three-hundred-page cipher report, my Dutch report and a long report on Belgium, but ‘no trace can be found of them’. Even the ditty-box has been ‘mislaid’, and there are only two documents in the archive which are directly attributable to me. The first is a lecture I’d given entitled ‘Be near me when my light is low’, and the other is my paper on ‘Ciphers, Signals and Sex’.

  To be fair to the Foreign Office, it has retained its sense of humour, whatever else it may have lost, and I was informed by the then curator that ‘Ciphers, Signals and Sex’ had been graced with a label ‘TO BE PRESERVED AS A DOCUMENT OF HISTORICAL IMPORTANCE’, but someone had crossed out ‘historical’ and written ‘hysterical’. Having reread it, I agree with him.

  A film was made about Violette Szabo called Carve Her Name with Pride, and I allowed its producer, Daniel Angel, to use the poem in his film providing that its author’s name wasn’t disclosed. Thousands of letters poured in asking who’d written it and the Rank Organisation professed not to know but felt they should send me a letter they’d received from the father of an eight-year-old boy.

  He said that his son was desperately ill, and could someone please answer the enclosed letter, which was written in code.

  I managed to break his baby code, and the clear-text read: ‘Dear code-master. She was very brave. Please how does the poem work. I’m going to be a spy when I grow up.’

  I replied to him in his code (this was essential), saying that as soon as he was better of course I’d show him how it worked. And as soon as he was better he might like to come to the Special Forces Club and meet some of the other agents he might have read about. In the meantime I was sending him a chess set which Violette once gave me because I knew that she’d like him to have it.

  Six weeks later I received a letter from his father saying that his son had rallied for
a month and had died with the chess set and the poem on his bed.

  In 1949 the Dutch government instituted a commission of inquiry to establish the truth about Holland. It was particularly anxious to discover whether the disasters had been caused by a traitor in SOE or whether Dutch lives had deliberately been sacrificed as part of a British deception scheme (a theory as prevalent then as it is today).

  The tribunal sat for almost a year and, as a gesture of goodwill, and to avoid any suggestion of a cover-up, the Foreign Office gave its chairman a list of SOE officers, from Gubbins downwards, who’d been ‘responsible’ for the conduct of clandestine operations in the Netherlands, and suggested that he should invite them to have frank discussions with him.

  Every one of them, including Gubbins, agreed to meet him, and their conversations took place between 3 and 10 October.

  It is doubtful whether a single participant in these ‘frank discussions’ could have shown the chairman how to break an indecipherable or assess the significance of a total lack of them.

  No member of the Signals directorate was invited to attend, though Nick and I were available at the time.

  It is possible that we’d have had something useful to contribute.

  APPENDIX ONE

  Fingerprinting WT Operators

  AWT operator’s touch on the keyboard was as individual as a fingerprint. This didn’t deter the enemy’s radio experts from trying to simulate it, and from the summer of ’43 until SOE stopped passing traffic, detailed recordings were made of every operator’s ‘fist’ before he or she left for the field.

  Method. The operators were instructed to transmit every letter of the alphabet at varying speeds, followed by every numeral, but were given no warning that they were being ‘fingerprinted’ to avoid self-conscious transmissions. Their dots, dashes and Morse hesitations were then transferred to a paper tape which moved at 16 feet per minute. This magnified even the smallest Morse dots by quarter of an inch, allowing an in-depth study to be made of every operator’s style. The details were recorded on square-ruled paper and lodged with the chief signalmasters at the WT stations. When the operators reached the field, their ‘fists’ varied from message to message, responding to the tensions of the moment, but the basic characteristics were always present. Yet the signalmasters needed no fingerprinting charts to identify these characteristics: their Morse-trained ears were attuned to every nuance of an operator’s touch, and they recognised it at once. The Funk-Horchdienst (the German interception service) was equally adept. Its radio experts were able to counterfeit our operators’ style to perfection if a sufficient number of messages had been intercepted.

  The only real value of fingerprinting was that it gave the operators confidence – which in itself was priceless. The concept of fingerprinting had been brought to Nick’s attention by a fair-haired WAAF officer named Kay Cameron, whose father had invented it. Nick immediately took her into SOE, as she was otherwise homeless. Determined that she should be based in London and posted to the stations only when necessary, he seconded her to the code department and asked me ‘to keep an eye on her’. As a contra-account (not that I needed one) he authorised me to headhunt young Captain Appleby, a camouflage expert from the Thatched Barn who was a genius at devising new hiding places for WOKs and LOPs.

  Shortage of space meant that Kay and Appleby had to share an office. They also shared an urge to help agents and each other in every way they could, and their enthusiasm for their near-impossible tasks turned their tiny office into a suite.

  Those close to them sometimes wondered if they indulged in mutual fingerprinting, and though this was a pointless speculation as they were experts at camouflage, it allowed us to forget for a few moments that the average life expectancy of a WT operator in France was at best six weeks.

  APPENDIX TWO

  Minute of 2 November 1943 from L.S. Marks, HQ Security & Planning Office

  INDECIPHERABLE MESSAGES ON LETTER ONE-TIME PADS

  Owing to the very simple construction of the letter one-time pad code it is most improbable that many indecipherable messages will be received. However, when these indecipherables occur, the following are the lines of attack which should be attempted.

  ATTEMPT NO 1

  Assume that the agent has written his message beneath his indicator group. Consequently, all groups will have to be moved one group to the left. If this does prove to be the case, in outward messages the Home Station should also write beneath the indicator group. There are two points to bear in mind, however.

  Firstly, if the agent sends a series of messages correctly and then suddenly makes a mistake by writing his message under the indicator group, the Home Station should not follow suit but assume that it is an error on the part of the agent. If the agent sends his first message with the clear-text written beneath the indicator group, the Home Station should reciprocate for his outward traffic until further notice.

  ATTEMPT NO 2

  The Outstation may be confused over prefixes, therefore the second as well as the first group of the message should be eliminated. This gives two attempts, i.e. eliminating the first two groups of the message and writing the third group as it should be written underneath the first group of the pad; and secondly, eliminating the first two groups and writing the third group underneath the indicated group of the one-time pad.

  ATTEMPT NO 3

  Should a message commence by reading sense, and suddenly break off into gibberish, the first group from which the gibberish appears should be moved immediately to the right, in case:

  a. a group has been omitted in wireless transmission, and

  b. the agent has slipped a group of his one-time pad when encoding his message.

  ATTEMPT NO 4

  The Home Station should now try to assume that the agent has written the message on top of the one-time pad groups instead of beneath them. Therefore, in order to decode, they should take the column of large capital letters on the extreme left of the substitution square, and this column should be regarded as the letters of the one-time pad. The small letters running along this line should be regarded as the letters of the cipher message. Letters at the head of the column in which the little letter stands must be regarded as the en clair group. For example, assume that the onetime pad group is ZVRBI, and that the agent has encoded the word ‘house’. Write the letters HOUSE ABOVE ZVRBI and the result is BIPJB.

  To encode to agents who are making this error, the first pair of letters for the Home Station to examine will be B over Z. They will go to b in the column at the extreme left of their substitution square and glance along until they find the little letter Z. When they have found Z, they must glance up and see in which column it stands. They will find it to stand in column H.

  The next pair of letters to examine will be I OVER V. They will go to column I at the extreme left of their substitution square and glance along until they find little letter V. When they have found V, they must glance up and see in which column it stands. It will be found to be in column O.

  Take P OVER R, J OVER B, B OVER I in the same manner, and the word house will be decoded.

  ATTEMPT NO 5

  It must be assumed now that the agent glances to the wrong side of his substitution square when enciphering, i.e. he will always look to the left of the capital letter instead of the right.

  ATTEMPT NO 6

  Assume that the agent, instead of taking the little letter as the cipher group and the large letter as the en clair, reverses the process and takes the little letter as the en clair group and the large capital as the cipher group.

  ATTEMPT NO 7

  In all cases where any great difficulty is experienced and the above methods fail, the Home Station must concentrate on the end of the message and try to work backwards, as it must never be forgotten that an agent may be passing a message for someone else and begin by Playfairing without giving us any warning. Caution must be taken, however, with the last group, which may consist of dead letters. The penultima
te group is really the key group at this stage of the attack.

  ATTEMPT NO 8

  When you find the agent’s indicator, assume that all the one-time-pad groups he has used consist of the groups immediately beneath this indicator group, i.e. in the same column instead of running along the same parallel.

  ATTEMPT NO 9

  It must also be assumed that an agent may omit a line, start on the wrong line or use the same line twice. He may also use the wrong page.

  The breaking of this code will depend very greatly on individual observation, as sometimes an agent will be merely a letter out, which means a sliding along to the left of one letter instead of five.

  The first attempt of all will therefore be a ‘fanning out’ in both directions, firstly group by group, secondly letter by letter. If this fails, the ‘fan’ must consist of two letters on either side being left out, then three, then four.

  In extreme cases, it must be assumed that up to ten groups of the pad may be omitted.

  Plates

  1. The author at his most mature.

  2. A WT operator disguised as a cow. He broadcast his traffic from a field in France. His antennae were housed at the rear, without causing morse mutilation.

  3. A portable WT set.

  4. Some of SOE’s silks.

  5. Portrait of Colonel Buckmaster.

  6. Portrait of Vera Atkins.