CHAPTER THIRTEEN

Interrogation and Infiltration

On Friday, 1 May Joseph Raskin was at the mission headquarters of Scheut. He celebrated an early mass and had breakfast before going to work in his room in the large brick complex. Around nine in the morning, the doorman knocked on his door to say he had a visitor. In the reception parlour was a local man called Laurent. He asked if Raskin was the father who had been to China. Raskin said yes. The man said he was a stamp collector. He wondered if Raskin would be interested in seeing some of the Chinese stamps from his collection. Raskin said he would be interested and that his visitor should come again. He walked the man out of the door of the reception building. As the visitor stepped out, he gave a signal. Two Germans walked in and grabbed Raskin by the arm.

They ordered the stamp man to tell Raskin in French that he had to take them to his room. By now, it was clear to Raskin that the stamp man was working for the Germans. He was Augustin Leduc, Bodicker and Plate’s best agent, sent to track down the priest who was using pigeons. Bodicker himself had been deeply involved in the case. Leduc’s orders were to confirm the identity of Raskin as a priest who had been to China. They knew for some reason that this was the key to identifying him as the priest who had been making use of pigeons. Leduc had been given orders to identify if the priest was there, and to give a signal to the Germans waiting outside if he was.

Others in the building realized something was going on. A milkman had just left after making his delivery to the basement but walked straight back in again to say the Germans were outside and they had guns. In just a few minutes, the building had been cordoned off. A car came into the grounds. Raskin was ushered into the back and before anyone else had the chance to say or do anything, it drove off, Raskin unable to utter a word. Their catch secured, the soldiers melted away and the priests and students began to emerge. Upstairs, the entrance to Raskin’s room was sealed. Printed on the seal were the words Sicherheit Polizei. The Germans conducted a thorough search after the arrest, taking away two suitcases full of evidence. They discovered a lab for making microfilms and canisters ready for the pigeons. But the statue of the Virgin Mary lay untouched in his rooms. Inside were the microfilms themselves. Everything had been ready except the pigeons.

Raskin was taken to the castle-like fortress of Saint-Gilles prison. It was a grim new home, crammed with prisoners who lived like troglodytes in bare stone caves surrounded by vaulted tunnels. The stench of cabbage and urine hung everywhere. But even here, resistance was possible for the determined. Raskin was alone, but other prisoners were given the job of bringing soup or bread or cleaning out his cell. ‘Call me Jan,’ one young man said as he emptied out a bucket. His next words were careful, since a guard was watching. ‘Prepare a message,’ he whispered before he left again.

Jan was able to go in and out of the cells to carry out cleaning duties. Next time he came, Raskin was ready and slipped a message to Jan, who placed it in his pocket. The prison was full of political prisoners who had learnt the skills of the clandestine world. A message had to be smuggled out person to person within the confines of the prison before it could reach someone who could take it into the outside world – a tiny replica of the long courier routes used to get messages out of Belgium and to England. One method was to use cigarette papers, onto which a message would be encoded, transcribed and then sent out.

Raskin wrote a series of notes and letters in the coming days which made it out through different routes. One was for the missionaries of Scheut and to Father Verhaeghe, who had known of his clandestine work. ‘I am sure about my death sentence,’ wrote Raskin. ‘Without grace or a miracle, my days are numbered. But God decides those days and I accept it completely.’ But, ever the spy as well as the priest, he was not going to give up without doing his best to survive, and to save others. He had a vital message. They must destroy the compromising documents he had hidden, and which the Germans had not found despite their search. The message was met with alarm by the leadership of Scheut, who feared what would happen if their headquarters came to be seen as a den of espionage rather than a place of prayer. So they decided to burn not only those documents but all Raskin’s papers. A case was found in the attic full of his notebooks, Chinese papers, drawings and watercolours, a life’s mementos of a cultured man. One father with an artistic eye saved some of the pictures and photos, but everything else was consigned to the flames.

Another note outlined the need to protect the broader Leopold Vindictive network. Raskin knew some in his network had not been arrested and he wanted to warn his friends. There was a list of names and addresses. These were people who had to be told as soon as possible of his arrest. He also wanted to assure people that he would not talk. ‘I name nobody,’ he wrote in this note. ‘But the others?’ The risk was that others would speak. ‘Mr Joye and Voske [Devos] should disappear immediately,’ he wrote. ‘Mrs Roberts also. It’s too dangerous.’ The Lichtervelde group should not worry, Raskin added. He would tell the Germans he had caught the pigeon without the Debaillies’ knowledge. Since he frequently stayed in their house and had his own room, he would simply claim he had found the pigeon, locked it in the bedroom and then released it. They were to say that it was normal for him to keep the door of his room closed and that they had known nothing about the bird. It was a barely believable story, but the best he could manage.

Raskin realized he was not the only one in trouble. He reported he had seen some of those he knew in the prison – including Van Hooff – and had heard the name Michelli. These names had to be passed on to others, especially Madame Roberts, he explained. Someone had to go to a shop called ‘The Little Doll’ in Antwerp and ask a series of women to pass her a message. The messenger must take care not to be followed, but the message was urgent. ‘They will all do this voluntarily but it has to be done in one day if possible as the hours are precious and the life of some of them depends on it.’

For some, Raskin’s warnings were too late. Madame Roberts had been arrested on 6 May, at the same time as Thonus and Van Hooff. Her ten-year-old son was smart enough to put out a warning signal to others she knew, and also burnt her papers and hid money linked to Raskin.

At a family party in Wallonia, Clément Macq had hurt his knee during a dance. He had been out of town for an operation but came home to his family hoping perhaps that no one had made the connection to him. The Germans rang his doorbell on the morning of 3 August. Leaning on a stick after the operation, even if he had wanted to run he could not have managed to do so.

Fritz Devos fled after the 6 May arrests. He saw a car come to pick up another associate, Julian Praet, who had been a helper moving the parachutists round Brussels. In the car, Devos thought he had seen Marcel Thonus. He believed the agent sent by MI6 was now talking to the Germans. Devos went into hiding, living under a series of false identities.

Hector Joye lay low and went to a friend for a month, but felt uneasy rather than safe. An aunt had tried to persuade him to hide in her convent. But Joye was a family man and he knew this was his vulnerability. If they could not catch him, he knew the Germans would take his wife or children. He felt he had no choice. He went home to Bruges on 10 June. Nine days later one of his sons was walking home when neighbours stopped him, telling him he should not go on as the Germans were there. He went anyway, arriving home to find his parents had been taken away and the house was being searched. His father’s office was sealed. His mother was released after a few days. Her small red diary records the transition of her life from worrying about matters to do with the school she ran to visits to Saint-Gilles and from the Gestapo. Appearing many times in the diary over the following weeks is a line saying simply that the Gestapo had come to the house to talk to her. The drawings of the Belgian coast carefully hidden by Joye in the frames of his kitchen door were not found, but the Germans did discover some military maps he had marked.

For the Debaillie family in Lichtervelde, those months as spring turned to summer were bleak. First Raskin, then Joye had been arrested. The pigeon had flown from their house. Arseen had been on the road with Joye. Every day was spent waiting for the knock on the door or the hand on the shoulder. The family feared those around them as well as the Germans. The village remained deeply divided between the blacks and the whites, the pro- and anti-Nazis, and suddenly the family could almost feel the atmosphere become more oppressive, as though they were watched and their activities known about. Rumours began to abound and whispers spread that the family was involved in some kind of resistance work, perhaps to do with the secret army who were said to be stockpiling weapons ready for the Allies to return. Denunciations spread and arrests began. The fear took its toll.

Michel – the fancier who had released the pigeon from the roof a year earlier – had always suffered from a weak heart and on 4 August 1942, the gentlest of the brothers was found dead early in the morning next to his bed. Amidst the anxiety over German arrests, he had suffered a heart attack.

On Saturday 8 August, the family gathered at 11 a.m. at the cemetery near the centre of Lichtervelde to bury him. The plot lies in the middle of the small cemetery, straight down a path from the single entrance by the road. Grief was mixed with fear for Arseen and Gabriel. The two surviving brothers had worried about the risks of being there that day. But to miss their brother’s funeral would confirm any suspicions the Germans might have. And they wanted to say goodbye.

Mourners waited in line by the grave to sprinkle holy water onto the coffin. Two men in civilian clothes strode down past the dark headstones that lined the avenue. They were neither friends nor family. They walked up to the black-clad Arseen and pulled him by the sleeve out of the line. They were not Germans but Flemish collaborators. Without saying anything he stepped away with them. Gabriel, standing beside him, was left alone. Young Rosa stood and watched as Arseen was led away to a waiting car, only dimly aware of what the others in the family knew – that they had come to bury one brother that day, and now had lost another.

Soon after, the Germans came to the house to look for Gabriel. Marie and Margaret said they did not know where he was. He had scurried into a hay loft and shifted to hide in the gap under the sloping roof of the house until morning, when he was sure they had left. He then stayed for a while with a friendly farmer. Word went round the village that he was dead – a letter from Gabriel to his family said he was going to drown himself. Instead the family had come up with an ingenious hiding place. In a downstairs room was a table for ironing with a cloth across it. The family dug down beneath the floor and created a hatch which opened up to a space only a metre or so square. Just enough for a man to curl up. Gabriel never left the house for the rest of the war, retreating into this space at the first sign of unexpected visitors or trouble. He never slept in his own bed for fear the Germans would come in the night. Even if he heard them coming and had time to hide, he was afraid they would notice that his bed was warm.

The question on everyone’s mind was the one that haunted all resistance networks. Had there been a traitor? Or had people just been sloppy? And had anyone talked under duress after they were captured? A bleak and depressing blame game began.

Some in the network were suspicious that Muylaert had talked after he was picked up in October 1941. Macq seemed to think Muylaert’s pride meant he was too boastful and not careful enough about whom he told of his work with them. Being a spy was not about showing off and vanity, Macq complained. He said he had always warned Raskin and Joye to be careful of him.

Certainly the Germans had interrogated Muylaert. We do not know what they did to him. Any fragments they may have obtained – perhaps over time, perhaps with torture – might have been used to complete the jigsaw puzzle of their investigation into who was in touch with the British. But there is no real evidence that he talked, and the time lag from his arrest to that of Raskin was too long – seven months – to account for it.

Some of Raskin’s Brussels helpers who worked with Michelli claimed Thonus had denounced the whole group after he was arrested, perhaps being treacherous even earlier. The Belgian Sûreté’s investigation shows no proof of that, although it does raise the possibility that Thonus was under surveillance, perhaps owing to his highly visible and reckless behaviour and general sloppiness after he arrived with Van Hooff. Thonus denied betraying anyone. He said that many people with whom he worked were not arrested, meaning he could not have talked. But, according to German police files, Thonus does appear to have given a partial confession, although exactly how it was extracted is unclear. He, like Michelli, may have been badly mistreated by the GFP. This led to further discoveries in what the files say was the basement of an insurance agent, probably Devos. Van Hooff’s last residence in Liège was turned over and his radio set found in working order. Slowly the Germans worked their way through the Brussels network and its wider connections across the country. Belgians and British airmen in hiding were found. At least forty people were initially picked up for interrogation. By November 1942, the number had risen to 225, according to German police reports.

Raskin was linked in the view of German investigators to the Dehennin group, which had been rolled up in October 1941. Since Raskin was arrested only in May 1942, and since Thonus and Van Hooff – the two agents sent in to contact him – were taken five days after his arrest, it may appear that all the May arrests were connected. But the same German team under Plate seem to have been following parallel tracks and only later realized there were connections between the priest and the others taken on 6 May.

The networks had been badly compromised. And because they were not compartmentalized, one compromise quickly spread to another. Large networks like Zero and Luc/Marc overlapped with smaller ones like Leopold Vindictive. They were all being rolled up too easily.

Raskin himself knew many people – that was his strength, and his weakness. That and his impatience. And as the hoped-for second pigeon failed to materialize, his desperation had driven him to try more and more routes. He had tried so many channels to get the map of the Belgian coast back to England that all it took was for one to be compromised for the authorities to be able to find him. In the end it looked as if more than one route was discovered.

After the church and his friends, Raskin’s smuggled messages also sought to protect the other pillar of his life – the royal family. Raskin warned that the Germans would have found two letters from the Comte de Grunne in his room. These were dangerous as they potentially revealed a connection between the royal court and someone now accused of being an MI6 spy. He told Father Verhaeghe to send a message to de Grunne saying that, if asked, they had only talked about family matters and the King’s marriage – and nothing else. In order to reassure them, he told Father Verhaeghe to let others know that he had said ‘I will never tell what connects me closely to the King.’

The danger of being linked to the royal family did however offer one hope for clemency. ‘The King (who knows me well) should ask the Führer to treat me mercifully,’ he asked. De Grunne had been alerted by Raskin’s sister to the arrest on 3 May, two days after it took place. On 11 May he wrote to her saying he had been away for a few days and had only just seen her letter. He said he would show it to the Queen Mother, Elizabeth, who knew Raskin. He added that he was sure she would try to intervene as far as she could, while warning that ‘in the present circumstances’ there could be no assurances as to what the result of such an intervention would be. Raskin still hoped that, despite all the incriminating evidence, his connections might get him out of the worst trouble. One thing he would never lose was hope.

But the royal route was slow. The Queen Mother was out of the country. It was only on 30 May that the royal court made a request to the authorities for the release of Raskin. By then it was already too late. He and his friends had been subject to what was known forebodingly as Nacht and Nebel – night and fog. Hitler had signed a decree six months earlier ordering that those found to be involved in resistance in occupied territories were to be secretly transferred and taken beyond the reach of normal criminal proceedings. Their families and friends would know nothing about their fate. On 11 May Raskin had already left Saint-Gilles. His destination was Germany. To his family, he had simply disappeared.

Word reached London on 5 May that something had gone wrong. A three-word telegram arrived at MI6. ‘Leopold Vindictive arrested,’ it read. It was from Van Hooff. The next day he too would be arrested. What had happened to them all, and why, was a mystery. On 1 July a message came in about the arrest of a radio operator; alongside it was another strange message saying ‘Vindictive is safe and has money.’ A mistake? Or a German deception message?

All this time MI14(d) and the Columba team had been in the dark. And that had been deliberate. Melland and Sanderson, who had so carefully unfurled those pages of rice paper in July the previous year, had no idea that MI6 had managed to establish contact with their precious source, let alone that they had gone so far as to parachute in agents to establish a connection. The MI6 files are closed, but one letter in the Columba archives points to what happened. The letter is dated 30 May 1942 and is from MI14 in response to a letter sent by MI6 two days previously. There seemed to have been a complaint from MI6 about an MI14 broadcast to Leopold Vindictive made on the BBC. MI14 confirmed that they had sent acknowledgements to Leopold Vindictive in July and on 25 September 1941 via BBC radio but had made no further broadcast until one which seems to have been transmitted just before the letter in May 1942. ‘I quite agree that in general it is perhaps inadvisable for messages to be broadcast to organizations on the continent with whom you may possibly be in touch, and I have instructed Melland to advise APS [Army Pigeon Service] not to arrange for broadcasts in these cases until we have discussed the matter with you.’

Then comes the damning sentence: ‘Had we known that you were in touch with Leopold Vindictive we would have spoken to you about him before.’ This makes it clear that MI6 had established contact with Leopold Vindictive but had not told MI14 – the organization whose pigeons had been the reason the network came into existence. ‘I very much hope that the broadcasts were not the main cause of his capture by the Boche. As he was, I understand, picked up by them early this month i.e. some eight months since the last broadcast using his nom-de-guerre, I feel this is on the whole unlikely,’ concludes the letter.

MI14 had been trying to re-establish contact through BBC messages without knowing that agents and radio operators had been sent out to meet Leopold Vindictive. It was only when MI6 heard those broadcasts that it suddenly felt the need to tell MI14 what it had been up to in order to get them to stop broadcasting. But by then it was too late. Word had been received already that Raskin had been arrested and the network rolled up. And poor MI14 was left in the position of having to argue that it was unlikely that its earlier broadcasts were to blame for the recent arrest. It is a damning indictment either of the secrecy of British intelligence or its lack of competence and coordination that two branches of the intelligence service could not keep each other informed about their links with the same resistance network. As SOE also found, such travails were a particular problem when it came to MI6, since it so jealously guarded its sources. That might be for the understandable reason of wanting to protect them against compromise by word getting out too widely, but it might also be simply for the bureaucratic reason of wanting to claim the credit for a successful source. In this case, the mistake seems particularly hard to forgive: it was MI14 that had first been in contact with Leopold Vindictive via the pigeons, and so it could hardly be blamed for trying to continue that relationship. And it was MI14 and Columba’s pigeons that Leopold Vindictive kept asking for.

For Brian Melland at MI14(d) there seems to have been something deeply personal about the connection with the bearded chaplain, whom he never actually met but whose words he deciphered with a magnifying glass. Melland seemed to remain anxious to solve the mystery of his fate. On 27 August 1942, he received a letter saying two people in England had arrived from a church in Flanders and knew about the evacuation of certain priests. ‘I give you this as of probably interest in connection with the famous number 37,’ he was told. Not just at the time but for years afterwards, members of Columba and MI14 would fear that their messages, broadcast on the BBC, had been the cause of the discovery of the Belgian priest. MI6 never seems to have told them the truth and put them out of their misery by explaining that the rot went much deeper.

The intelligence networks of both MI6 and SOE in Belgium were falling apart in the spring of 1942. And the problems were compounded because both organizations were so slow to realize it. Parachuted radio operators like Jacques Van Horen had been captured and their radio sets used by the Germans to send false messages, but it took far too long for London to become aware of this. Van Horen was not an isolated case. British operations in Belgium were badly penetrated by German intelligence (although not quite as catastrophically as in the Netherlands, where every single agent dropped was captured). The story of operations makes for a grim account of arrests, betrayal, failure and denial.

There is often a kind of denial within intelligence services when things start to go wrong, an unwillingness to admit that this is due to more than chance but rather because an operation has been compromised. SOE slowly realized something looked wrong with an operation called Manfriday/Intersection in the middle of 1942, but as late as September senior figures thought it was still running smoothly. Only as they examined the record more closely did it began to dawn on SOE that things had gone badly wrong.

MI5 began an investigation. The verdict was dire. Almost every Belgian radio set was being run by the Germans. By autumn 1942, German success in Belgium meant – according to the official SOE history – that the agency’s ‘organization in the field was no more than a mirage created by the Gestapo’. The year had been ‘operationally disastrous’, SOE’s own files record. By October 1942, Hardy Amies’s Belgian section had dispatched forty-five agents to Belgium. Thirty-two were in enemy hands.

Van Horen, who had been in touch with Michelli, was a prime example of the failure to accept what was happening. An MI6 agent had reported on 28 April – before the Leopold Vindictive arrests – that ‘Van Horen arreté et parlé’ – he had been arrested and talked. This was passed onto SOE since he was primarily their agent. But London remained in denial that he might have been captured, let alone worked with the Germans. In late July another message came out through the Zero network to Page at MI6 suggesting there had been arrests. But the truth only began to sink in in mid-October when Van Horen managed to have a letter smuggled out through Sweden. It bore three words: ‘Suis en prison’ – I am in prison. By November SOE staff realized that Van Horen and another agent, Weasel (who had been reporting successful sabotage operations on generators and bridges), were under enemy control. It still took until December for British intelligence to realize that Van Horen might have been cooperating with the Germans for months before the September message. No one knew for sure since when.

MI5’s investigating officer complained about the terrible state of SOE files on Belgium. The organization was often lauded for its daring but it was also sloppy. Agents were of poor quality. The codes they used were weak. In some cases, the identity check an agent was supposed to give at the start of a radio message was wrong, and yet such errors were ignored by SOE because they happened so frequently, making the whole exercise worthless as an indication of whether an agent was under German control. Some SOE agents betrayed everyone – in one case his brother, sister-in-law and niece, even the doctor who had set his ankle, which he broke on his drop.

The damning MI5 investigation also raised concerns over the sending of pigeons for agents. The Van Horen compromise was an example of the danger involved.

Columba itself had been the route for a German deception operation. Containers of money and weapons for the ‘secret army’ were dropped by SOE for Van Horen at the end of May; further consignments were sent in the following months. Their receipt was confirmed by pigeon messages signed ‘Jean of the Reception Committee’. ‘A thousand thanks for the money and good food,’ Jean wrote on 29 June. Another message congratulating the RAF pilots for their skill ended, ‘Long Live the freedom of the United Democracies.’ These messages came through Columba and are written on the standard pink sheets used by the team. ‘This time we had to wait quite a bit,’ reads one message from September, which also asks for confirmation that the last pigeons had arrived in London. ‘Please do not forget to send us some more Sten guns for which all the boys are asking.’ The last message, in November, sends particular thanks for some letters dropped to pass on to the ‘Chief’, who is said to be still in France and also asks for two bottles of whisky. All these messages had been sent by Abwehr IIIF. One can only think that the German intelligence officers who had been running the network enjoyed their drink very much.

MI5 noted in its investigation that the pigeons carrying these messages sometimes only returned with the acknowledgement a month after the containers had been dropped. And ‘Jean of the Reception Committee’ was not a prearranged form of signature. The MI5 investigator assumed that SOE did not have a clue who this person actually was. The use of pigeons in Van Horen’s mission and that of another compromised agent was ‘thoroughly unreliable’ and ‘highly undesirable’, the MI5 officer thought. ‘It appears to me to amount to little more than presenting the Germans with a channel of communication to this country by which they can send any message they like.’

The MI5 investigation also noted that as well as SOE’s problems with the Belgian Sûreté (who broke off relations for a while), MI6’s secrecy did not help. MI5 knew about their sister service’s operations in Belgium. ‘SIS have also got some finger in the pie, but exactly how they operate is not known,’ the MI5 officer notes, adding that communications from SOE agents, including some letters, were often received through MI6. This was the confusion in the field which had caused such a problem with Michelli’s network. Some of the SOE agents who came into contact with agents run by MI6 and the Sûreté in Belgium and asked for help were refused, MI5 noted. This was on MI6 instructions, the order being given on the grounds of security because MI6 feared further compromise. The ‘bad blood’ between the two services was thereby increased.

MI6’s secret – one that it kept from MI5, SOE and others in London – was that it, as much as its rival service, was struggling in Belgium. Thonus and Van Hooff were among a number of trained wireless operators sent into Belgium by MI6 in the spring of 1942, and the supply of intelligence had initially appeared to improve. By June they seemed to be receiving comprehensive railway and troop information. But they too were losing agents. Many were being captured almost immediately on arrival – far more than would be expected assuming the normal level of risk.

In March 1942, following a wave of arrests linked to the Zero, Beaver and Brave networks in Belgium, Claude Dansey had begun to worry. In the same month that Page and MI6 sent Van Hooff and Thonus to contact Leopold Vindictive, he told Page that ‘unless some drastic steps are taken with or without the consent of Lepage you will soon be without any agents left in Belgium.’ In light of the SOE experience, Dansey wanted to check if any wireless operators in the field were compromised. Then they could ‘devise some steps to save what is left’. The knowledge of compromise did not, it seems, stop more agents being sent in, including the men sent to meet Raskin.

Urgent meetings with MI5 would be held in late 1942 and early 1943 to try to establish what was going wrong. MI5 wondered if the problem was due to compromised wireless sets or if something more serious was going on. Could there be a traitor, not in Belgium but in London? Remarkably, some even wondered if Lepage himself – the head of the Belgian Sûreté – could be the traitor. As agents paid the price in the field, the war between SOE and Lepage became even more vicious. Starting in spring 1942, SOE had drawn up a dossier of accusations against the head of the Sûreté. Too many agents were burnt. There were too many ‘coincidences’ – an agent was arrested a few days after Lepage complained about a Frenchman being used as a saboteur in Belgium. A whole network of people linked to the case appeared to have been arrested in quick succession. Together this had all ‘cost the lives of several men’. ‘It is a remarkable coincidence that in every case of an independent agent becoming known to the Sûreté he has immediately become under suspicion and has subsequently been arrested,’ SOE argued. The charge could not be more serious – that Lepage was selling out SOE operations to the Germans, resulting in the arrest and death of agents. A senior officer at SOE jotted a footnote on a report from Amies saying there was a rumour that the Sûreté sent over to Belgium photos and descriptions of SOE men so that they were always caught.

The extremes to which SOE was willing to go are surprising. There was discussion as to whether they could use a contact who had gone to work in the Sûreté to steal any incriminating documents from a safe. They wondered if someone ‘would be able to get something just or unjust’ on Lepage and perhaps plant an incriminating letter from the Germans in the diplomatic bag to frame him. SOE’s anger had blinded it to its own faults. Lepage was difficult and was playing his own game, but there was never any evidence he had deliberately blown operations. It was all too easy to look for someone else to blame.

MI6 also received warnings of possible treachery in London. A CX report – the name given to an item of raw intelligence – of 13 June 1942 came from a courier. It was passed on to SOE, although with reservations that it had not been confirmed. It said: ‘Germans have full knowledge of projected parachute landings in Belgium.’ A few months later, another man who arrived in Britain as a refugee passed on a verbal message he had been given: ‘Mme Sauvage of Liège wishes to inform the British Intelligence Service that Parachutists destined for or released over Belgium, are betrayed by someone in London, and there are frequent arrests soon after their landing. The capture of such men has taken place after the arrest in London of the paymaster of the Parachutists Corps here. Mme Sauvage insists on the fact that it is quite impossible for the Germans to find out in Belgium the exact place and date of such landings and she is quite sure the leakage must be looked for on this side of the Channel.’

Could a traitor inside British intelligence be responsible? There were fears of treachery everywhere, but the MI5 verdict was that the source of the problem were agents in the UK, who after their training were often loose-lipped about their work, sometimes in London’s bars and nightclubs. Such was the worry that a person was planted at the instruction school to keep an eye on whether operations were being compromised there.

But if there had been a compromise – perhaps the man who had approached Van Hooff at his hotel – there is no sign it was discovered. There were some traitors within MI6 in the war, notably one called Hooper who had become an agent of the Germans in the late 1930s and ended up working for MI5 and then MI6 on Dutch operations. But no one has ever been discovered dealing with operations in Belgium at the time. Treachery was too easy an excuse. The truth was that SOE and MI6 were in a mess in Belgium, poorly organized, their teams overlapping and easily penetrated, and so were struggling against an effective enemy.

For some in London, the knowledge that agents were being sent into terrible danger was a source of real pain. Hardy Amies struggled over whether the lives lost were worth it – especially because he felt the gains from SOE’s sabotage activity in Belgium were relatively meagre. ‘There were many moments – and I still have a guilt complex about it – when I felt once or twice I ought to resign because I thought my heart was not in the thing,’ he reflected after the war. ‘I thought this is lunacy – we are just sending people to their death.’ His only reason for staying was that even if the successes were few they kept up morale, and that if he quit someone would just take his place.

Claude Dansey at MI6 had a different view. When his man in MI9, Jimmy Langley, wanted to do more to help agents working on the evasion line who had been captured and condemned to death, Dansey lashed out. ‘One of your failings is that you are too damned weak,’ he said. ‘Your trouble is, Jimmy, that you love your agents.’

And as the members of the group that represented its greatest triumph lay in a Brussels prison, Columba itself was about to go through its own darkest hour amid accusations of betrayal. The two founders would depart, and pigeon politics, with its bizarre personalities – including an occult-obsessed viscount – would nearly consume Columba’s work.