‘Coffee, please. White, no sugar,’ Saffron said.

  ‘I’ll see to it,’ said Pamela.

  There was a door beyond the two desks, which now opened to reveal William Stephenson. He focused on Saffron with his searching eyes. ‘Good morning, Saffron. Come in and let’s get started.’

  ‘That’s quite a view,’ said Saffron as she entered Stephenson’s office. At the far side stood a sleek, modernist desk, on which three telephones – black, white and red – and an intercom box were arranged in a neat line. Beyond it, two large windows looked across the plaza towards Fifth Avenue and the cathedral.

  ‘It’s not bad,’ Stephenson agreed. ‘But there are better. Now, let’s make ourselves comfortable over here.’

  To one side of the room, a large framed map hung on the wall, showing Canada, the United States and the westernmost waters of the North Atlantic. Below it, two low, chrome-framed leather-upholstered sofas faced each other across a glass-topped table on which a brown manila file had been placed. Stephenson sat down by the file and motioned to Saffron to take a seat opposite him.

  Pamela slipped into the room and silently placed two cups of coffee on the table. Saffron gave her a smile of thanks. Then she took her place, crossed her legs, smoothed down her skirt and waited for Stephenson’s opening move.

  ‘So, about your mission to Washington . . .’ he began. ‘I had my staff get in touch with a number of political and military figures whom I know to be sympathetic to the work SOE is doing. I underlined the importance of getting Allied agents into Occupied Europe, and gave them a few details about you. There was an excellent response. You will not be short of invitations to business meetings and social events. Both, in my view, are equally important.’

  ‘Thank you,’ Saffron said simply.

  Stephenson reached for the file. ‘This is a dossier that we prepared for you.’ He slid it across the glass tabletop. ‘It lists all your contacts, times of meetings and events, locations and so forth. There are half a dozen social invitations in there, too. We RSVP’d on your behalf.’

  Saffron picked up the file and then set it down, unopened, on the table in front of her. ‘That’s very kind,’ she said. ‘What I’d really like, though, is some advice on what to say, what questions to ask, what buttons to push to persuade these men to look favourably on SOE.’

  ‘I thought you might. The dossier also contains a list of talking points, and outlines the things these men want to hear. The main question you must be able to answer is this – how can SOE help the invasion of Occupied Europe when it comes? The only thing that matters to anyone in Washington is getting from the French, Belgian or Dutch coast to Berlin, as fast as possible, with the minimum number of dead Americans. If SOE can help with that, then you’ll be in business.’

  ‘Well, I can answer that question right away,’ Saffron said. ‘And I can do so on the basis of having been in both Belgium and Holland within the past few months and seeing the situation at first hand.’

  ‘Good. Always start that way. It’ll get everyone’s attention. Now, let me play the guy from the Pentagon . . . What did you learn over there about the people’s resistance to Hitler?’

  ‘As matters stand, there’s not much of it,’ Saffron responded. ‘There are very few people in resistance movements, and their efforts are sporadic and mostly ineffective.’

  ‘Why’s that?’

  ‘The majority of people in the occupied nations are too frightened to rise up against the Germans. They know that if they get caught, they’ll be interrogated, tortured and then executed without the benefit of a trial. From the perspective of the average Dutch or Belgian, it seems the Germans are going to be there forever.’

  ‘If that’s the case, why should we help you?’ Stephenson pressed. ‘What good can you do?’

  ‘Because the tide of the war is turning. Once the French and Belgians and Dutch can see that the Germans are losing and that the Allies are on their way, then they will be ready to take action. And that’s where the SOE comes in. We can supply local people with weapons, ammunition, explosives, radios. We can train them to bomb railway lines, assassinate local army and SS commanders, and carry out attacks on German patrols and motorcycle messengers. That all adds up to effective, destructive action that will tie up a great many German troops and make it harder for them to defend their empire in Europe against the invading Allied armies. And that will achieve both of the ends you specified – faster progress, fewer casualties.’

  Stephenson gave a grunt of approval, which, Saffron guessed, was as good as a round of applause from a more demonstrative man. ‘Good. That will go down well in Washington. Now, tell me, do you know personally how to undertake all these bombings, assassinations, ambushes and so forth?’

  ‘Of course. We were all trained to do that.’

  ‘Then I advise you to go into a few details – the tougher and bloodier, the better. Coming from a woman, that will get their attention.’

  ‘By all means, if you think it would help,’ Saffron said.

  ‘I do.’

  ‘Then that’s settled.’ One aspect of Saffron’s journey to Washington had been wrapped up. Now she wanted to change the subject. ‘I owe you an awful lot for all the help you’re giving me,’ she said. ‘I feel I should do something in return. Brigadier Gubbins said you had something in mind. “Sleuthing” was the word he used. What exactly does that entail?’

  Stephenson almost smiled. ‘I was wondering when you’d ask. And the simple answer is that I need you to find out why a man has stopped sending letters to his godson. Because the success or failure of the greatest seaborne invasion in human history may depend on the answer to that question.’

  ‘Oh . . .’ said Saffron, unable to come up with a better comment on a mission that was so overwhelmingly important and so utterly baffling.

  ‘Let me explain,’ Stephenson said.

  He got to his feet and walked over to the map on the wall. ‘There!’ he said, jabbing at a small pink dot on the map. ‘That is the island of Bermuda, six hundred and some miles east of Cape Hatteras, North Carolina, and a British colony since 1607.’

  ‘I hear it’s a lovely place for a holiday,’ Saffron said.

  ‘Indeed it is. I strongly recommend it. But that’s not why I’m pointing it out. I want to tell you about the one thousand, two hundred of your countrymen and women who are spending this war in the Princess Hotel, otherwise known as the Pink Palace, which is one of the oldest, biggest and smartest establishments on the island.’

  ‘They’re not on holiday, I imagine.’

  ‘No, they have to do a lot of tough, often boring and repetitive work.’

  Stephenson left the map and sat back down on the sofa. ‘Three years ago, while the United States was still neutral, I helped negotiate a deal between the US and British governments by which all mail leaving the United States bound for Europe was intercepted and taken by flying boat to Bermuda, to be read by staff of British Imperial Censorship . . .’

  ‘I didn’t know there was such a thing,’ Saffron said.

  ‘That’s the point – people not knowing.’

  ‘Can I ask how you got the Americans to agree to that deal while they were still neutral?’

  ‘With some difficulty. I argued that we would be able to help the US as well as Britain by uncovering Nazi spies based in America. The FBI didn’t like that. Mr Hoover reckoned he could catch Nazis all by himself, thank you. The project hung in the balance for a while. But then we caught a lucky break. One of our people in Bermuda noticed a letter addressed to a gentleman called Lothar Frederick. And that was interesting, because “Lothar” was a code name for Reinhard Heydrich, who was second only to Himmler in the SS.’

  ‘Until SEO assassinated him.’

  ‘Indeed you did . . . Anyway, to cut a long story short, there were regular letters from a man who signed himself “Joe K”, and they contained messages in invisible ink, plus diagrams of, for example, the US defences at Pearl Harbor.’

  ‘Goodness! That’s serious stuff.’

  ‘Very. Our discovery started a process that ended with the FBI uncovering an entire Nazi spy ring. And Joe K, alias Kurt Frederick Ludwig, is currently cooling his heels in Alcatraz and no one complains about Bermuda anymore.’

  Saffron thought for a moment. ‘Would I be right in thinking that your people in Bermuda have uncovered another spy, by any chance?’

  ‘You would be exactly right,’ Stephenson replied.

  ‘But you’re talking to me, not the FBI, because . . .’

  Stephenson said nothing, letting her complete the thought.

  Saffron pondered for a second. ‘You don’t want them to know what you think is happening. And why wouldn’t you want that? Why do you want to keep this in house? Okay . . . You’re worried that this spy is one of us, aren’t you?’

  ‘Yes. I believe there is a spy working for the Germans in the British embassy in Washington. And within the next three weeks, Mr Churchill and President Roosevelt, along with their key military strategists, will sit down together to determine, amongst other things, the course of the war in Europe over the next twelve to eighteen months—’

  ‘Including the invasion.’

  ‘More than one invasion, I would imagine. There’s more than one way into Europe.’

  ‘So, if the Germans were to know our plans, that would be a total disaster. And if the Americans found out that it was all because of a spy in our embassy—’

  ‘Yep – that would make it an even bigger disaster.’

  ‘Still, don’t you have to tell the FBI about your suspicions, no matter how awkward it might be?’

  ‘Uh-huh.’ Stephenson nodded. ‘Pretty soon I won’t have much choice. But what if Hoover advises the president that it’s not safe to be meeting with Mr Churchill? The thought of the prime minister being sent back to Britain, having accomplished nothing . . . Think what that would do for morale in Britain, and what a gift it would be for Nazi propaganda.’

  ‘Do you know anything about this spy? You must do, or you couldn’t have worked out he was there . . . whoever he is.’

  ‘That’s a good question. Let me get the person who is best able to answer it.’ Stephenson got up and walked to his desk. He pressed a button on the intercom. ‘Grace, could you please ask Miss Araminta Keswick to join us?’

  Stephenson returned to the sofa, moving himself up to one end to make room for another person. ‘The young lady you are about to meet has a high level of security clearance. You and she can discuss your work in the certain knowledge that none of what is said will go any further.’

  The door opened and Saffron turned her head to see a plump, bespectacled woman, dressed in grey trousers, a plain white shirt and a rather baggy pale blue cardigan. Her mousy hair was pinned into a ragged bun, from which stray wisps had escaped in a number of different directions. She was holding a manila folder, identical to the one that Stephenson had given Saffron.

  Miss Keswick’s smile as she saw Saffron was tentative, shy and distracted, as though her mind was somewhere else. But as she came closer and their eyes met, Saffron sensed a high-powered mind. Miss Keswick took her place on the sofa and glanced across at Stephenson. ‘Would you like me to explain about Gerald now, sir?’

  ‘Go ahead.’

  ‘Well, then . . .’ Miss Keswick gathered her thoughts and began her story. ‘One day in the middle of January last year, I opened a letter to a Master Oskar Nykvist, in Östersund, Sweden.’

  ‘It’s a town in the middle of the country, a little less than four hundred miles from Stockholm,’ Stephenson explained.

  ‘Yes,’ said Miss Keswick, ‘and as I opened the envelope, I said to myself, “I wonder what Gerald is sending you this month.” You see, I’d seen two of these letters before, and, as it later turned out, a couple of other girls had opened ones like them before me. And as I said those words, it suddenly struck me – “Is there something fishy going on here?”’

  ‘What made you think that?’ Saffron asked.

  ‘Well, the letters were always dated the eighteenth of the month. They were sent every month, regular as clockwork, and they were all just signed “From your loving Godfather, Gerald.” They were nice, cheerful letters. They seemed harmless. But there was something about that regularity. It didn’t seem like the way a godfather keeps in touch with a young child.’

  ‘But it is the way an agent communicates with their handler,’ Saffron observed. ‘So that if the schedule is ever broken, the handler knows something’s wrong.’

  ‘But the thing that really niggled at me,’ Miss Keswick continued, ‘wasn’t the schedule. It was that the letters were written entirely in English – not a word of Swedish. Of course, Gerald could just have been helping Oskar to learn English, but you’d have thought that he’d still have thrown in the odd word in the boy’s own language, maybe at the beginning, or when he was sending his love at the end.’

  ‘I agree,’ said Saffron. ‘If Gerald’s close enough to the family to be a godfather, he’d know a bit of Swedish. Could you tell anything about him from the letters?’

  ‘Oh, yes. For a start, it was definitely an Englishman writing, not an American. That was obvious from the language he used. He was quite charming, actually.’

  ‘Could it have been someone pretending to be English?’

  ‘No, I don’t think so. The tone seemed genuine. I knew the type of chap he was, too – well educated, from an upper-class or upper-middle-class family . . .’

  ‘Public school, in other words.’

  ‘Absolutely. And I don’t believe that a foreigner could get it quite right, without any giveaways. Well, not unless they’d lived or gone to school in England. And even then, there would be the odd word or phrase that gave them away.’

  ‘Tell her about the pictures,’ said Stephenson.

  ‘Absolutely, sir,’ said Miss Keswick. ‘So, Gerald’s letters always contained an image of some kind. The first few were black-and-white photographs taken in Washington DC, presumably by Gerald himself. But after a while he switched to colour postcards of something typically American that would appeal to a small boy. Mickey Mouse, for example, or a shiny Cadillac, or a painting of Chief Sitting Bull. And there would always be a couple of lines in the letter about the postcard, but the card itself was blank, because, as we gathered from the letters, little Oskar was supposed to stick them all in an album which Gerald had given him for his birthday.’

  ‘That’s neat,’ said Saffron. ‘Was there a hidden message written on the blank side of the card?’

  Stephenson smiled. ‘Nice try. But no.’

  ‘You got there quicker than we did, though,’ said Miss Keswick. ‘Even after I’d flagged the Gerald letters as something that could be of interest, it took three more messages before anyone at the Pink Palace asked that question.’

  ‘An error, but understandable,’ said Stephenson. ‘Our people in Bermuda are dealing with tens of thousands of letters a week. Those Gerald letters were akin to a few grains of sand on a mile-long beach.’

  ‘Of course, as soon as we thought there might be something on the cards, we started taking the whole thing very seriously,’ Miss Keswick continued. ‘We’ve got some terribly brainy boffins. They tested them with every method of detecting invisible ink they knew, but they couldn’t find a thing. Then I had a eureka moment. The answer had been staring us in the face all along. The message was on the picture, not the blank side.’

  ‘You mean, like a microdot?’ Saffron asked. ‘We have a magic tricks department at SOE that dreams up all sorts of gadgets, and I know they’re working on that for us, too. An agent writes a message, photographs it, reduces the image to a microscopic size, and then sticks it onto . . . well, almost anything. And of course!’ Saffron suddenly exclaimed. ‘The words Gerald wrote about the card in the letters told the person at the other end where to look for the microdot.’

  ‘That’s right,’ said Miss Keswick. ‘Let me show you.’ She opened her file and started shuffling through the papers. ‘Once we decided we needed to keep an eye on the Gerald letters, we started photographing them all. So . . . ah . . . yes . . . Here is the postcard of Sitting Bull I was talking about.’

  Miss Keswick handed Saffron a Victorian era image of Sitting Bull looking at the camera. His face was stern and commanding; his hair rested on his chest in two long plaits, and a single, magnificent feather was stuck vertically into the hair at the back of his head.

  ‘And here is the letter that came with it. I’ve underlined the key words – “Isn’t that feather splendid, sticking up behind his head?” The boffins looked at the bottom of the feather, just where it poked up behind his head, going over the whole area under a microscope. It took a while for them to find the microdot, but they got there in the end.’

  ‘So how is the agent creating his microdots?’ Saffron asked. ‘As I understand it, that’s a sophisticated procedure and it needs a lot of gear. Whoever’s sending these messages must be well equipped.’

  ‘That’s not all. When we finally got into the microdot, we found a message that no one has been able to decode.’

  Before Saffron could follow up, Stephenson put an end to the conversation. ‘Thank you, Araminta, that was an excellent presentation. But I can take it from here.’

  ‘She seems very bright,’ said Saffron, as the door closed behind Miss Keswick.

  ‘Oh, yes. She was recruited from Girton College, Cambridge, where she was lecturing in linguistics while working on her PhD thesis – “The Mathematics of Language”. She has a particular interest in finding linguistic patterns that have characteristics similar to mathematical patterns, like the Fibonacci sequence.’

  ‘I should have thought that would make her the perfect cryptographer.’

  ‘You’re not the only one to hold that view. We’re having a hell of a fight to keep her. I fear Miss Keswick will soon find herself on a flying boat to Britain.’