Between Silk and Cyanide

by Leo Marks

  The great decoder of unconscious signals had left Austria in 1938 to seek sanctuary in England and he’d found some for himself amongst the bookshelves of 84. Freud was seldom well enough to leave his Hampstead home and couldn’t climb the stairs to the third floor of 84, where rare religious and occult books were housed. Frank Doel, the shop’s anchorman, had gladly carried down to him everything that he’d wanted to see. He was particularly interested in anything which had a bearing on the life of Moses.* He was too ill to visit Marks & Co. again and died in 1939. As compensation for arriving five minutes too late to see him sitting there (J. B. Priestley had pulled out a chair for him), I was given signed copies of The Interpretation of Dreams and The Psychopathology of Everyday Life. They were addictive and should have been issued on prescription only.

  I tried with uninformed enthusiasm to apply their principles to the psychopathology of SOE life. According to my understanding of Sigmund, I was in the market for Joan Dodd’s sexual stationery, felt that my parents should be starving instead of the Grouse and knew in my unconscious exactly what was wrong with the Dutch traffic.

  It must be a very dark night down there. The knowledge still refused to surface.

  From all that I’d heard about SOE’s director of Finance, he was as good at causing nightmares as Freud at decoding them. Group Captain Venner had been in SOE long enough to believe that he knew every fiddle there was. He was convinced that I’d worked a new one and was determined to find out how I’d managed it.

  I had forgotten that my two WOK-makers could not live by codes alone and that someone would have to pay them a salary. That someone was Group Captain Venner.

  The unauthorised employment of two lowly paid civilians hardly seemed to warrant the personal attention of a member of the Execu-tive Council, but I was duly summoned to Venner’s office for a full accounting.

  He wasted no time in skirmishing. ‘I want to know how those girls got here.’

  I began to explain the importance to SOE of the work they were doing.

  ‘I don’t give a damn if they’re planning the invasion of Europe. I want to know how they got here.’

  ‘They are planning the invasion of Europe, sir.’

  ‘What?’

  I explained that we were going to invade it with a new code, which the girls were making by hand, and that to vary the drudgery they helped Grendon to break indecipherables.

  The office was filled with that most despairing of sounds, a finance director’s sigh. ‘Will you please tell me how they got here?’

  ‘By bus, sir.’

  I was afraid he was about to send for the fraud squad. Its SOE equivalent was Major O’Reilly.

  ‘What are indecipherables?’ he suddenly asked.

  He hardly had time to cover up his secret documents before I was seated by his side giving him a potted version of how indecipherables were broken. I showed him why the permutations could run into tens of millions. He did a quick calculation on his pad and nodded. ‘Do we get many?’ he asked.

  Anyone who’d say ‘we’ in circumstances like this must be a good man to work for.

  ‘Some weeks we get none, sir. But most of the time they come at us from all over Europe. We get them from the Free French, the normal French, the Danes, the Norwegians, the … You’ve been an absolute godsend, sir. May I go now?’

  I rushed back to my own office before he could answer.

  The unconscious signal had finally reached its Home Station and only God and Freud would know how I’d missed it.

  With the exception of Parsnip’s traffic, which was passed by Boni, we had never received an indecipherable from Holland which had been caused by coding mistakes.

  It was then that I realised the implications.

  There was an essential piece of homework I had to do before trying to convince SOE of what the absence of indecipherables from Holland really meant. It was vital to establish whether Parsnip’s indecipherables had been caused by Morse mutilation or mistakes in his coding. If it proved to be the latter, he was the only Dutch agent who was behaving normally.

  Putting the code groups of his seven indecipherables side by side with Boni’s clear-texts, I was about to start on a cryptographic jamboree to reconstruct whatever mistakes in coding Parsnip might have made when I remembered that his indecipherables had all been concerned with intelligence matters. I also remembered that the Dutch section’s traffic had twice referred to a special code (Playfair) which Potato used for passwords and addresses. Supposing Parsnip were using a special code for his intelligence messages and for some reason we had no knowledge of it?

  I telephoned Bingham and demanded that he talk to me. Yes, of course he’d given Parsnip a reserve poem for his Top Secret intelligence messages. Yes, of course he’d informed Dansey which poem he’d selected, and yes of course he’d confirmed it in writing, there must be a memo on file. What was all the fuss about anyway? I told him that it was just a routine check.

  And of course there was no such memo on Dansey’s meticulous file, and of course Dansey had not been told by Bingham which reserve poem Parsnip was to use for intelligence messages. We had tried a blanket attack on the wrong code.

  Every one of Parsnip’s messages came out perfectly on his reserve poem, and I was ashamed that I was glad. I could now say without any qualification to whoever would listen to me that no Dutch agent had made a mistake in his coding …

  It was time to consult Heffer, the only man in SOE with whom it was safe to think aloud.

  Why were the Dutch agents the only ones who never made mistakes in their coding? Were they all Knut Hauglands? Or were their working conditions so secure that they had as much time as they needed to encode their messages and didn’t have to worry about Germans on the prowl?

  And could the Abor/Ebenezer security-check anomalies still be attributed to bad training and forgetfulness when that same bad training, that same forgetfulness, made them into flawless coders?

  How much reliance could really be placed on the Dutch section’s assurances that they regularly monitored their agents’ safety? Were they relying on the reports of agents who might themselves be captured?

  And was the traffic snarl-up no more than a natural hazard of clandestine communication? What about the four messages from London which Parsnip and Potato had been unable to decode? I’d checked and double-checked every one of them and they’d been encoded perfectly. Were Parsnip and Potato pretending they couldn’t decipher them to postpone answering difficult questions and to avoid meetings which they couldn’t possibly attend?

  Heffer blinked, which was his way of holding up his hand, and asked what my conclusions were.

  I put to him that indecipherables were a black plague and that there was only one feasible explanation for the Dutch agents’ immunity from it. They were operating under duress.

  He warned me that I was basing my conclusions on a negative inference. The Dutch section and others were likely to say that the ‘discovery’ was no more than coincidence or a specialist juggling with statistics. He advised me to look into it more deeply and prepare a written report for Nicholls, who’d be back in a week’s time. I knew then that he took it as seriously as I did.

  Showing signs of duress himself, he stressed the importance of finding supporting evidence that the agents had been caught. Inspired guesses only produced inspired excuses. He warned me against saying anything to the Dutch section prematurely. They might send a message to the field asking why there’d been no indecipherables.

  He expressed, if the term were applicable to his tempo, interest in knowing what had pointed me in this direction.

  I didn’t tell him that it was a combination of Group Captain Venner and Air Commodore Freud.

  The first thing to establish was who was actually encoding the messages. Was it the agents under supervision? Or were the Germans doing it themselves? The only way to determine this was to study the coding habits of every Dutch agent.

  I took the clear-texts of all t
he messages which had been received from Holland since June ’42 and encoded them as the agents had. It was a long and exhausting process, and I found that by the end of it I’d made many mistakes and that two of my messages were completely indecipherable. According to Freud, this was likely to be deliberate.

  A pattern emerged which was not quite distinctive enough to be called a style. It was based upon a freedom of choice. Every agent could pick any five words of his poem for his transposition keys. Agents tended to have favourite words and often used the same combination for a number of messages. These words either had an emotive value for them or they were the easiest to spell. But above all, agents favoured the shortest words they could find because they minimised the tortuous process of numbering the key phrases.

  The Dutch agents were perfectly normal in their ratio of favourite words to new ones. I noticed that Boni never chose a key phrase without the word ‘wish’ in it. They were also normal in their choice of the shortest words – with one exception: Ebenezer regularly used at least two of the longest words at his disposal. For one message he’d even used three, making his transposition key over twenty letters long. Done by Haugland, it was an example of a first-class coder. Done by Ebenezer, it could mean that he had plenty of time for his coding and showed a marked departure from an agent’s norm. The question was, was it the norm for Ebenezer?

  I contacted his training school to check the length of the key phrases he’d used in his student days, but his training messages had long since been destroyed. The instructor reminded me that it wasn’t until July ’42 that London had ordered the training schools to retain every agent’s practice messages. I was familiar with this instruction. I’d sent it myself in the name of Ozanne.

  It didn’t help with Ebenezer but I was now able to examine the coding exercises of every Dutch agent who’d been sent into the field since July ’42. They’d been average to good coders and each of them had sent a trainee’s normal quota of indecipherables. Yet not one Dutch agent had repeated his early training mistakes when he reached the field.

  This put the Dutch in a class apart.

  So did their wireless habits.

  Reports from the Grendon signalmasters showed that the Dutch WT operators made as many procedural errors as other agents and that their traffic was as prone to Morse mutilation. But with the exception of Boni, not a single Dutch WT operator had asked the Home Station to repeat a message on the grounds that it had been garbled in transmission and couldn’t be deciphered. This was an important discovery but it had to be kept in perspective.

  Grendon’s transmitters were powerful and the operators highly trained and the incidence of agents asking for repeats of messages was small. But it had happened several times in every country section except the Dutch.

  The agent who’d come closest to it was Ebenezer. In April ’42 he’d suddenly terminated a sked because of interference. Even so, he had never asked for London’s messages to be repeated.

  Why was it, then, that this same interference, which so troubled other countries’ agents, hadn’t caused the Dutch to send or receive a single indecipherable, with the possible exceptions of Parsnip and Potato?

  I broke off at this stage to summarise for Nicholls my findings to date. I reported that, on balance, I thought that the Dutch agents were doing their own coding and that their messages were being checked by the Germans before transmission. I couldn’t yet specify how many agents had been caught or who they were, but at least a large question mark had to be put against the names of Abor, Ebenezer, Boni, Trumpet and Potato.

  The next phase would determine whether I could produce any substantive proof. It would be the first time that I had studied a country section’s traffic for its content alone.

  I read through every message which the Dutch section had sent to the field and compared each one with the agent’s replies. It needed a trained Intelligence officer to do this job properly. The traffic contained so many disturbing implications that halfway through a second reading I went back to the beginning to make a precis of the principal exchanges. It was like trying to synopsise the Domesday Book.

  When the precis was finished I listed the dropping operations in chronological order with the names of the agents involved. Remembering that Nicholls was a professional soldier, I refrained from adding a layman’s comments. That was the most difficult part.

  Ebenezer and Thijs Taconis (referred to in messages as ‘Tall Thijs’) were dropped into Holland in November ’41. Their early traffic was mainly concerned with bread-and-butter intelligence and the problems of setting up communications. Ebenezer’s first message was received on 3 January and his skeds, which he kept regularly, were on alternate Fridays.

  On 28 February two more agents, Jordaan (Trumpet) and Ras (Lettuce), were dropped near Holten. Trumpet was referred to in messages by his field name, Jeffers.

  On 15 March the Dutch section instructed Ebenezer to find a dropping ground for a new agent and a number of containers. The operation was code-named Watercress and would take place in the next moon period. Ebenezer replied that he was looking for a dropping ground and would prepare a reception committee.

  On 17 March London informed Ebenezer that Taconis had found a dropping ground near the banks of the Reitdeip Canal. Ebenezer was instructed to prepare it for Watercress. Ebenezer replied that the Reitdeip dropping ground was too isolated and suggested that the drop should take place on the moorlands near Steenwijk.

  It was in this message that he began his peculiar spelling of ‘stop’ as ‘stip’, ‘step’ and ‘stap’, and omitting his secondary security check.

  On 25 March the Dutch section agreed to accept Steenwijk and informed Ebenezer that Abor would be dropped there within forty-eight hours. He was instructed to arrange the ground lights in the form of a triangle; the reception committee should identify itself to Abor by using the name Ebenezer.

  On 28 March Ebenezer reported that Abor had been dropped safely with four containers.

  On 29 March Lieutenant Andringa (referred to in messages as Akkie) and Jan Molenaar (Turnip, field name Martens) were dropped near Holten.

  Also on 29 March Ebenezer was instructed to find out what had happened to two agents who’d been dropped on 10 March and had failed to contact London.

  On 4 April Ebenezer replied that one of the agents had been killed on landing and he was trying to establish contact with the other.

  On 5 April Kloos (Leek) and Sebes (Heck) were dropped into Holland. Their arrival coincided with a series of messages from the Dutch section of Ebenezer asking him to find out what had happened to Akkie and Martens, who had been out of touch with London since their arrival. Ebenezer reported that he’d had no success in tracing them.

  On 9 April Trumpet informed London that he had just met Akkie at a safe house in Haarlem. Akkie wanted London to know that his WT operator Martens (Turnip) had been killed on landing. Akkie still had Turnip’s signal plan and he wanted Trumpet to use it and be his WT operator until London could send a replacement.

  The Dutch section at once agreed that Trumpet should handle Akkie’s traffic and promised to send a new WT operator during the next moon period.

  Lieutenant de Haas (Potato, field name Pijl) was landed by motor torpedo boat on the Dutch coast on 19 April. He was the first Dutch agent to be equipped with a Eureka. He was to link up with Akkie. His messages were to be passed by Ebenezer.

  On 24 April Trumpet sent London an urgent message over three hundred letters long. It was so disturbing that I put an asterisk against it and against the messages it gave rise to, and then erased them. It was better for Nicholls to insert his own.

  Trumpet informed the Dutch section that Leek and Heck could not communicate with London as their WT sets had been lost on landing. They had contacted the Lettuce group to ask for WT facilities. (Trumpet was Lettuce’s WT operator.)

  Trumpet went on to say that Pijl (Potato) had also been in touch with him. Pijl had been unable to communicate with London because he
couldn’t contact either Thijs (Taconis) or Ebenezer, who were to send his messages for him. Trumpet had agreed to pass Pijl’s traffic until Thijs or Ebenezer could be reached.

  The Dutch section at once sent a message to Thijs via Ebenezer informing him that Pijl had been trying to contact him. Thijs was told to make arrangements through the safe house at Haarlem to meet Pijl. Taconis replied via Ebenezer that he would contact Pijl immediately.

  This was the start of independent circuits of agents being put in direct touch with each other, all of them dependent on Ebenezer, Boni or Trumpet for their traffic.

  On 20 April Trumpet informed London that Akkie had found a reliable local WT operator. Trumpet wanted London’s authority to recruit him and teach him SOE’s WT procedures. The Dutch section agreed to this request but stipulated that the new operator must send a test signal to London.

  On 30 April the Dutch section informed Trumpet that the new operator’s test signal was satisfactory but that he’d omitted his security checks. Trumpet was given specific details of these checks in the same message.

  I put six asterisks against this one, then erased five of them.

  On 2 May the Dutch section instructed Ebenezer to prepare a dropping ground on the Steenwijk moors for a large number of containers. Ebenezer confirmed that the dropping ground was ready. The drop took place without enemy interference.

  On 11 May the Dutch section sent Pijl a message via Ebenezer’s set instructing him to find suitable points along the coast where agents and equipment could be landed at night. He was to use his ‘special equipment’ for the first time.

  This ‘special equipment’ was a lamp which emitted an invisible infrared beam which signalled its position to a receiver on board a ship. The landing party would thus be able to pinpoint the spot where Pijl and his reception committee were waiting.

  Pijl replied via Ebenezer suggesting several suitable landing points on the coast and the Dutch section selected Katwijk.

  On 17 May Pijl sent a message that he and a reception committee had waited at Katwijk all night but that the ship had not appeared.