The Mom Who Stole the Blueprints for the Atomic Bomb.

No one likes to be underestimated or overlooked because of something as unchangeable as X and Y chromosomes. But sometimes there are advantages to being underestimated.

Ben MACINTYRE: There was Mrs. Burton. And by day, she was looking after her children and going to church and cooking. But in fact, in the privy, in the outside toilet, in the back garden, she had built a very powerful radio transmitter with which Colonel Ursula Kuczynski of the Red Army was sending the blueprints for the atomic bomb back to Moscow. 

Ursula Kuczynski was a Jewish German citizen. She worked as a spy for the Soviet Union from 1930 to 1950, relaying America’s scientific secrets to the U.S.S.R. — and helping to intensify the Cold War. Her neighbors in the English village of Great Rollright knew her simply as Mrs. Burton. Her code name was Agent Sonya.

MACINTYRE: I’m Ben Macintyre. I’m a columnist for The Times of London. And I write intelligence histories. 

Ben Macintyre has been fascinated by spies since he was young. In a different life, he might have become one himself.

MACINTYRE: You asked why I ended up in this strange world. Well, it was mostly accidental. I was recruited by MI6 before I left university.

Instead, he wound up tackling the subject in his nonfiction books. Some of those New York Times best-sellers include A Spy Among Friends, Operation Mincemeat, and The Spy and the Traitor. That last book received some high praise from the late John le Carré, the legendary spy novelist — and former spy himself. Le Carré called it the “best true spy story” he had ever read. But, even after decades immersed in the world of covert operations, Macintyre had never come across a spy quite like Ursula Kuczynski. For one thing, she’s the first major spy he’s written about who is a woman.

MACINTYRE: The fact that she was a wife, and a mother, and a woman was also her greatest disguise. It made her almost invisible to the people hunting her.

Here’s Ben Macintyre reading an excerpt from his newest book, Agent Sonya.

*      *      *

The villagers of Great Rollright did not know that in her last mission of the war Mrs Burton had infiltrated communist spies into a top-secret American operation parachuting anti-Nazi agents into the dying Third Reich. These ‘Good Germans’ were supposedly spying for America; in reality, they were working for Colonel Kuczynski of Great Rollright. 

Her codename was ‘Sonya’. This is her story. 

*      *      *

This is The Freakonomics Radio Book Club. Ben Macintyre discusses his book, Agent Sonya: Moscow’s Most Daring Wartime Spy. Today’s host is Sarah Lyall, writer-at-large for the New York Times and the author of The Anglo Files: A Field Guide to the British.

*      *      *

You know when you’re watching a spy movie, and they’re using codenames, code words, and writing things in invisible ink, and you think, some of this has got to be made up, right? Well, it turns out that a lot of that code-language is actually used by real spies.

Sarah LYALL: I feel like I should be starting this interview by saying something like, “Do you like ice cream?” Or “Stout is no good. I prefer lager.”

MACINTYRE: That’s exactly what it was, is “Do you like ice cream? No, I prefer whiskey.” If you’d overheard it, you’d have thought that’s clearly two spies having a secret exchange. Wouldn’t you? Only the Mafia and the police, I think, are more interested in their own mythology than spies. Spies are completely obsessed with spycraft even when it’s completely unnecessary.  

LYALL: But when you read, for example, the books of John le Carré and you read all these details about the elaborate efforts that they went to conceal themselves and to leave messages and do the drop-offs, you think it has to be fiction.

MACINTYRE: I think that’s true but even before John le Carré, spies were avidly reading their own fiction. And then, the fiction in turn informs the reality.

LYALL: I’m wondering how you yourself became interested in this line of work.   

MACINTYRE: Well, it was mostly accidental. I was recruited by MI6 before I left university. On the last day at Cambridge, my don, as we call them, my sort of moral tutor, as we knew them approached me and over a glass of warm sherry, said, “Ben, there are parts of the Foreign Office that are different from the main parts of the Foreign Office in the sense that they are different from the Foreign Office.” He never actually said what it was I was going to go and do, but it was pretty clear to me where he was heading. And we all knew stories of people who’d been “tapped up,” as they say, by the intelligence services. So, I rattled off in my best suit and had a series of, well, in retrospect, hilarious interviews with a man who couldn’t have been further from my image of James Bond. And I was rather off-put by my first meeting with this gentleman because he was wearing a suit, sure enough, but wearing sandals with socks, which was not at all what I imagined a spy ought to be doing. And we had a hilarious interview during which he sort of told me a little bit about what the job would be like and then asked me a few questions. And I think both sides realized that I was not ideal for this job, because as I’ve just demonstrated, I find it quite hard to keep a secret. 

LYALL: Did you think, ‘This is ridiculous’? 

MACINTYRE: I thought it was both ridiculous and wonderful, like being in your own film really, suddenly thinking, “Gosh, I’m heading off to go talk to spies. This can’t really be happening.” I also had the problem of what to wear. I wasn’t quite sure what a spy ought to wear, really, whether you should underplay it or overplay it. I can’t even remember what I did now, but I definitely carried what I thought looked like quite a sort of spy-like attaché case. I had a very old, rather beautiful leather attaché case, which I thought was exactly the sort of thing that a spy would wander around in.

As much as he loves classic spy mythology, Macintyre was drawn to his most recent subject Ursula Kuczynski, in part, because she was so unconventional.

MACINTYRE: There are lots of women spies in history, from Mata Hari onwards, but they tend to be agents. They tend to be people who are recruited by intelligence services and then required to do or persuaded to do a certain thing. Ursula is different. She’s a pro. She regards being a spy as a vocation. For the first half of her career, she was a ferocious opponent of fascism, so she was spying against Hitler and trying to bring down the Nazi regime. And then, in the second half of her career, after the end of the Second World War, she was spying against the Brits and the Americans, to try and gather the secrets that the Soviet Union wanted. So, her life in some ways is a life of two parts. 

LYALL: You talk about her life being a “whirlwind of espionage, child-rearing, and housework.”

MACINTYRE: This is, in a way, the emotional core of the book, — the tension between what Ursula saw as her ideological duty to forward the cause, and her responsibilities as a mother and as a wife. And she took both very seriously. But which would have taken precedence if it had come to that is one of the things that I think troubled her for the rest of her life. Even in old, old age, she once remarked, “I think I was a good spy, but I wonder if I was a good mother.” Don’t let’s forget that she wasn’t just putting herself in jeopardy. If she had been captured, she would have been deported back to Nazi Germany with her family and they would all have been murdered. So, it wasn’t just her own life that was at stake. But I think one has to be a little careful of a double standard here, because we wouldn’t ask of a male spy of that period, “Were they a good enough father? Were they a good enough husband?”  

LYALL: You talked to her two sons for this book. What happened to her daughter? 

MACINTYRE: Her daughter died  before I came to the project. But I had extensive conversations with both her sons. And they were particularly poignant, I felt, about this question of the mother that they had known and the mother that they had discovered, as it were, in later life. Michael was particularly touching about it because he said, “I didn’t know it. But there were many, many secrets going on. And secrets are toxic. Secrets are addictive. Once you have tasted secrecy, it’s a very difficult drug to renounce. The discovery that my mother had lived this double life,” he said, “has affected me forever. And he said, “I’ve been married and divorced three times. Maybe it’s that I never really learned to trust anybody.” 

LYALL: She married this nice, nice, hapless man who had been in love with her, who she thought was a little bit boring, but was there waiting for her, Rudi Hamburger.

MACINTYRE: Rudi was given a job working for the British-run Shanghai Municipal Council. He was an architect, a man of charm, perhaps not a very strong character in lots of ways, nothing like as strong as Ursula. But so they arrive in Shanghai, which is this boiling, roiling mixture of expats and criminals and drug dealers and gangsters and very, very wealthy traders and entrepreneurs and so on. And she plunges into a sort of expat life there. And she finds it utterly boring. And she found she was pregnant. And in the heat of Shanghai, it was all very difficult to deal with. And her marriage to Rudi is already beginning to fray somewhat.

Ursula’s dull new life in Shanghai changed when she met a man named Richard Sorge — the man who would introduce her to espionage. Ian Fleming, the creator of James Bond, once described Sorge as “the most formidable spy in history.”

MACINTYRE: He was German-born, Soviet-trained officer in the Red Army Intelligence Unit, and he was going up through the ranks very quickly. He was a man of high intelligence. He was an extremely adept seducer. He was a prodigious gatherer of secret information.

Sorge was introduced to Ursula by a fellow communist spy in Shanghai.

MACINTYRE: They met in the house where Ursula was living at the time. And he said, “I understand you’re a communist. I understand you’re willing to work for the party here.” Initially, her job was really just to operate a safe house, to operate a place where Sorge could meet with his underground contacts. But very quickly, she became more important to his operation. She began passing messages. She began gathering intelligence on her own behalf. She even ended up looking after the arsenal and the archives of this network, which was an extremely dangerous thing to do. And one day Sorge turned up quite soon after she’d had her first child. The baby was perhaps about eight months old at the time. And he arrived on his enormous, German-made motorbike and said to Ursula, “Would you come for a ride in the countryside?”  He knew the seductive power of a large motorbike.

Here’s that moment in the book.

*      *      *

Sorge was a fantastically reckless driver. Soon they were beyond the city limits and flying through the Chinese countryside, past paddy fields and villages, Ursula’s arms tightly wrapped around Sorge. ‘Thrilled by his breakneck driving, I urged him to go faster and faster.’ Sorge accelerated, and the motor-bike seemed to take off. Ursula was in a state of petrified ecstasy. 

‘When we stopped,’ she later wrote, ‘I was a changed person. I laughed and romped about and talked non-stop.’ Her anxieties seemed to evaporate. ‘Shanghai’s detested social life was forgotten, as were the constant pressures to conform to etiquette, the responsibilities of clandestine activities, and the unnecessary worries about my son … I was no longer afraid.’ Many years later, she reflected: ‘Perhaps he had only arranged this ride to test my physical courage. If, however, he had been seeking a way to establish better contact between us, he had gone about it the right way. 

*      *      *

LYALL: It’s another thing that’s interesting about being that age and being a romantic, it’s easier to long for people who aren’t there anymore than it is to get along with the people who are there.

MACINTYRE: I think that’s a really good point. Look, the relationship with Sorge was never going to last. I mean, she didn’t know it, but he was already married. He had children. There’s a whole area of his life that she knew nothing about. And you’re absolutely right. It’s part of the function of a very active imagination, to sort of idealize your world and to think yourself into this romance. She really loved him until her dying day. And I think that for the rest of her life, to some extent, she was doing this for Richard Sorge, even though their relationship lasted a very short time. I mean, it was only a year later that he whipped back to Moscow and then was redeployed to Japan. And she never saw him again. Rudi, her husband, knew absolutely nothing about what she was really up to. He had no idea that these spy rendezvous were taking place, let alone that she was having a relationship with Sorge. Although, he would eventually find out, inevitably. 

LYALL: He put up with more than almost any husband I’ve ever heard of.  

*      *      *

Spying is highly stressful. So are bringing up a child, running a household in a foreign country and concealing an extramarital affair. The demands on Ursula required both a genius for compartmentalizing the different areas of her life and intense psychological stamina, as she juggled her rival commitments to husband and lover, bourgeois social engagements and communist subversion, her baby and her ideology. ‘Underground work cut deeply into my personal life,’ she wrote. ‘Rudi was as good and considerate as ever, but I could not talk to him about the people who were closest to me or the work on which my life centred.’ Under the twin pressures of espionage and infidelity, her marriage was falling apart. 

*      *      *

LYALL: I love your discussion of the tension between her job and her family life.  

MACINTYRE: It’s an astonishing piece of multitasking, particularly when you combine it with the fact that she was also a wife and a mother of three. But of course, that was her great cover. It made her almost invisible to the people hunting her because, particularly in the mid-20th century, nobody could imagine that somebody who appeared to be a perfectly ordinary housewife could actually be a saboteur, bomb maker, courier, secret agent, radio transmitter, an expert, all of those things at the same time. 

By 1938, Ursula had begun running operations herself.

MACINTYRE: Before going to Switzerland, she recruited two British communists. One of them was called Alexander Foote. And he didn’t even really know he was spying for the Soviet Union. He didn’t really ask many questions. 

LYALL: Which is quite odd, isn’t it? 

MACINTYRE: It’s quite odd. But he was 25. He was a pretty feckless individual. Somebody came along and said, “Look, would you like an adventure? And here’s a pot of money. All you have to do is go and sit in Munich and make friends with a lot of Nazis and we’ll get back to you.” And he said, “Yes, fine, I’ll do that. That sounds great.” His Communism was pretty lightly worn. I don’t think he read a word of Marx or Engels. It definitely wasn’t—.

LYALL: What a horrible communist. And then, he turns up at this restaurant. 

MACINTYRE: Well, that’s the most extraordinary element of the story of all, one that completely gobsmacked me, really. He took to taking lunch in the Osteria Bavaria, which was a restaurant in downtown Munich. And the second or third time that he was there, Hitler came in with his entourage, marched in into a semi-private dining room at the back there. And it turned out that the Osteria Bavaria, was Hitler’s favorite restaurant in Munich. And Hitler made a point of dining there every time he was in town. 

*      *      *

I’m Sarah Lyall, and this is The Freakonomics Radio Book Club. Today we’re speaking with spy-chronicler Ben Macintyre about his latest book, Agent Sonya: Moscow’s Most Daring Wartime Spy. At this point in the story, Ursula is living in Switzerland. One of her agents in Munich, Alexander Foote, discovers that his go-to lunch spot — the Osteria Bavaria — is, coincidentally, the favorite restaurant of Adolf Hitler.

MACINTYRE: Foote also took to dining there whenever he could. And when he reported this back to Ursula, he said, “Look, it’s extraordinary.” He said, “Whenever Hitler’s in town, he turns up. And he’s not very well defended. It would be very easy to kill him.” And in fact, Foote was really just making a joke. But that’s not how Ursula took it. She heard this and thought, “Right, that’s it. That’s the opportunity.” And she reported back to Moscow. And inevitably Moscow said, “That’s a really, really good idea.” And by this point, Ursula and Foote had been joined by a man called Len Beurton, who was another veteran of the Spanish Civil War. He was another recruit to Ursula’s network. And he, too, began to have lunch in this place with Alexander Foote. And the two of them, with Ursula’s help, thrashed out this plan to blow up Hitler. Ursula was going to build a bomb. They were going to carry it into the Osteria Bavaria, leave it next to the partition and then blow the Führer to smithereens. And of all the assassination plots against Hitler, I would say this was the one that was most likely to succeed. They could easily have pulled it off. And it was weeks from being put into operation when the Molotov-Ribbentrop Pact — the brief non-aggression pact between Nazi Germany and the Soviet Union — was announced. And Ursula received a wireless message saying, “Call off all offensive operations against Germany immediately.” 

*      *      *

Ursula was shocked to the core. Without warning, Moscow had suspended offensive operations against the regime that had forced her family into exile, destroyed the German Communist Party and begun the systematic slaughter of her fellow Jews. She had fought fascism all her adult life, in Germany, China, Manchuria, Poland and now Switzerland; she had repeatedly risked her life for the Soviet Union; and now communism, the cause she loved, was in league with Nazism, the creed of racist violence and death she detested. 

*      *      *

LYALL: That was one of the very interesting things that you bring up so well in this book, that the opposition to the Nazis was in some ways inextricably linked to communism.

MACINTYRE: I mean, we look back on this period really through the prism of the Cold War. We see communism for the threat that it became to our way of life and to Western values after the war. We often tend to forget that in the 1930s, for many people on the left, the Communist Party appeared to be the only defense, the only people who were prepared to shed blood in the opposition to fascism. And to understand someone like Ursula, who grew up between the wars in Weimar Germany when fascism was on the march, when Hitler was on the rise, when the brownshirts were on the streets, to a young, idealistic person like Ursula, there really seem to be only one way to stand up to this horror.

LYALL: Tell me a little bit about her background and how she became politicized. 

MACINTYRE: Well, Ursula Kuczynski came from an upper-middle class, fairly wealthy, Jewish family. Her father was a demographer. She grew up surrounded by books and intellectual stimulation and some very distinguished people. I mean, Einstein, for example, was a close friend of her father. These artists and intellectuals were constantly passing through their house, they had a very large house in Schlachtensee in an exclusive suburb of Berlin. They lived a good and highly intellectual life with absolutely no premonition, obviously, of what was coming to German Jewry. One of her formative experiences was during the May Day parade of 1924. Workers took to the streets with banners and were brutally suppressed by the Berlin police force. And Ursula was really quite badly beaten by a German policeman with his truncheon. And she came home very bruised. And it sort of solidified for her, I think, an absolute determination not to be done down by the forces of the establishment and the right, as she saw it. 

*      *      *

The tumultuous 14-year period between the fall of the Kaiser and the rise of Hitler is seen as a time of mounting menace, the backdrop to the horror that followed. But to be young and idealistic in those years was intoxicating, edgy and exciting, as the world went mad. War debts, reparations and financial mismanagement triggered hyperinflation. Cash was barely worth the paper it was printed on. Some people starved, while others went on lunatic spending sprees, since there was no point keeping money that would soon be valueless. 

She would remember her teenage years in the Weimar Republic through a series of politically tinted images: ‘The wealth of the small, privileged circles and the poverty of the many, the unemployed begging at street corners.’ She resolved to change the world. For Ursula was ambitious and confident: she would transform society in more radical ways than her father, and she was determined to be a better mother than her own. These twin ambitions would not always sit comfortably together. 

*      *      *

LYALL: And she was an avowed communist the entire time. She never, ever wavered in her ideological views.  

MACINTYRE: It’s not quite right to say that she never wavered. There were moments in her life, particularly in the late 1930s, when the Stalinist purges were underway. And her friends and colleagues were being systematically murdered by the Stalin regime. And it’s one of the elements of Ursula’s life that makes for a fairly queasy reading. The one thing I wish I’d been able to ask her, is, “How much did you really know, or not know, about what was going on?” I do think there was a certain amount of not wanting to see what she didn’t want to see. And she was scared. I think she knew that as a woman, as a foreigner, as an intelligence officer, she was right at the top of the potential hit list and that she was in real danger. But interestingly, even right at the end of her life, she would say, “I didn’t do this for Stalin. I did this for the sake of an idea. And while that idea has been perverted in the wrong hands, I still believe in that idea.”

By the late 1930s, Ursula had divorced Rudi, and was still operating out of Switzerland. She had two children now, the first from Rudi and the second from a different communist spy. Later, she would have a third. But her concern now was that the Nazis might invade Switzerland.

MACINTYRE: She’d managed to evade all the people who were hunting for spies like her in Switzerland. But her passport was running out. It sounds like such a mundane thing, but as a German Jew, she was going to be unable to get a new passport. And so, she realized that she had to do something in order to get out of Switzerland. So, she hit on a plan to marry Alexander Foote. Rather to Foote’s astonishment, she asked Foote if he would marry her. And Foote said, “Oh, yes, of course. I’d be delighted to marry you.” Because then she would get a British passport as his wife. It was a marriage of convenience. Foote then had second thoughts. So, she turns to Foote’s No. 2, this Len Beurton. And she says, “Well, Len, will you marry me?” And Len says, “Yes. Yes. I’ll marry you. Of course, I’ll marry you.” And it’s quite funny. She said to Len, “Well, of course, it’ll just be a marriage of convenience. We’ll divorce as soon as you want.” And he looked mortally offended and said, “Yes, of course, I understand that.” But in fact, the truth is that Len had fallen in love with Ursula. And they would get married and she would get a passport and they would remain married for the next 50 years. 

Ursula had a nanny named Olga Muth, who went by Ollo. Olga had started working in the Kuczyniski household in 1911, when Ursula was only 3. Now she cared for Ursula’s three children, and travelled with the family. The arrangement worked well for years. “I never mentioned the nature of my work,” Ursula wrote. “And Ollo did not ask about it.”

LYALL: And that nanny is living with her in Switzerland and having a bit of a nervous breakdown.  

MACINTYRE: When Olga Muth discovered that Ursula was not only getting married, but was getting a British passport and therefore had a way to get out of Switzerland, Olga Muth had a sort of breakdown. She believed that Ursula was about to abandon her and that therefore she would be deprived of the little girl whom she had become very besotted with actually, Ursula’s younger child. And so, poor old Olga Muth decided that if she went to the British authorities in Switzerland and explained that Ursula was a spy for the Soviets, the British would then not issue her with a passport and they could all remain in Switzerland and live happily ever after. Ursula got wind of this attempt by her nanny to betray her. And this is where the domestic and the international espionage merge in a most extraordinary way, because the greatest threat to her life comes from her beloved nanny. And there’s a terrible moment when she and Len had worked out what was going on and briefly contemplated whether they would actually have to murder the nanny.

*      *      *

Len was firm. ‘During the Spanish Civil War he had looked death in the face many times.’ Unless Ollo was stopped, she could get them all killed. ‘Would she go to the Swiss authorities, or would she even go so far as to contact the German fascists?’ Espionage is a lethal profession, as Ursula was well aware. ‘The past had required me to deal with death more than once.’ But the idea of ‘liquidating’ Olga Muth, whatever her treachery, was more than she could bear. Ollo had risked her life for Ursula. They could not kill her, and she would not give Moscow the opportunity to order her to do so.

*      *      *

Ursula smuggled her children away from Olga Muth and broke ties with her. Now that she was married, Ursula could get a passport and could enter the U.K. — but this was still a big risk. With her communist ties and frequent travels, she would seem to be a target for British intelligence. Or so one might think.

LYALL: How did she end up getting in? Like, How did MI5 miss this opportunity to nab this spy mastermind? 

MACINTYRE: I mean, again, there is sexism at play here because the authorities did suspect both of them of being communist sympathizers. But they were much, much more interested in Len, in the husband who’d fought in the Spanish Civil War, than they ever were in Ursula. And this is the period of the Molotov-Ribbentrop Pact. So, they were looking very closely at communists. And there was the sense that because the Nazis and the Soviets were in this sort of temporary alliance — didn’t know it was temporary — that they might represent an equal threat. On the other hand, when the Molotov-Ribbentrop Pact ends, British intelligence virtually stopped looking at any communists and focused entirely on the German threat. So, it’s a hinge moment. They keep a sort of half eye on her for a while. And later on, there are these really killingly funny elements in the files where police are sent to look at Ursula, and they say, “Well, it can’t be Mrs. Burton because she — you know, she bakes very nice scones.”

LYALL: They’re annoyed because she’s sort of dowdy. They’re like, a real spy wouldn’t be as drab.

MACINTYRE: I think possibly only a woman would have been able to see through Ursula’s disguise. And that woman was really the only senior counterintelligence officer who was a woman in MI5. And Milicent Bagot was this tremendous, formidable, unmarried, tough cookie. I mean, she was a proper anti-communist expert. She knew more about the communist networks in Britain than any other intelligence officer. And she was one of those wonderful women who always wears a hat indoors and didn’t brook fools gladly and always sang with the Bach Choir every Tuesday. But she very early on was saying to her colleagues,“The whole Kuczynski clan is dodgy. We need to do something about this We need to put phone taps on them. We need to follow them.” And it was just constantly ignored by her male colleagues. I mean, it is funny, but it’s also slightly chilling when you look back and think just how duped they were, really. 

Ursula, her children, and Len arrived in England just before Operation Barbarossa, the Nazi invasion of the Soviet Union.

MACINTYRE: And when that happens, she manages to re-establish contact with Soviet intelligence via the Soviet embassy in London and she’s back in the game. She builds herself a radio, and she begins to set up her own network of informants in Britain. Don’t forget she is military intelligence. So, her main job is to gather military information. Britain and the Soviet Union were technically allies. That didn’t stop the Soviet Union from spying on Britain and in particular on the atomic weapons program, which really became the high watermark really of Ursula’s espionage. 

LYALL: The fact that she could do this was both an incredible tribute to her skill and, again, a little bit of a failure of British intelligence, right? 

MACINTYRE: Yes, I think both of those assessments are precisely right. It wasn’t easy to pick up spies inside the atomic weapons program. On the other hand, the academic community in Britain was very welcoming to German scientific refugees. They realized that they really needed them. And one of those that was welcomed with open arms by British academia, was a man called Klaus Fuchs. Fuchs was a prodigiously talented young physicist who had fallen foul of the Nazis, escaped to Britain, and very swiftly was taken into the — into the heart, really, of the atomic weapons program. What nobody knew was that he was also a committed communist, and he felt that it was unfair that Britain and America were secretly developing an atomic weapon without telling their ally, the Soviet Union, what they were doing. And actually, his political views were really no more sophisticated than that. He wanted to level the playing field. And Ursula recruited him via her brother Jürgen and began to extract from him an astonishing amount of material. In the end, something like 590 pages of what were effectively blueprints for building the atomic weapon were passed by Klaus Fuchs to Ursula Burton, and she would either radio this back to Moscow using her homemade radio, or she would leave it in a special dead drop site in the root of a hollow tree for her Soviet controller to pick up and then send back in the diplomatic bag to Moscow. 

LYALL: What is a dead letter drop? And how did their dead letter drop work? And why didn’t anyone catch them doing it?

MACINTYRE: Well, a dead letter drop — sometimes known as a dead letter box— is where you leave a message for someone else to pick up at a prearranged point, but you never have physical contact with them. So, it’s a way of sort of maintaining distance. And in Ursula’s case, her main dead letter box was a hollow tree, three trees beyond the crossroads, beyond the railway crossing, outside the little village of Great Rollright, deep in the Oxfordshire countryside. Because by this point, Ursula was living with her husband, Len, and her three children in the village of Great Rollright, which is a hamlet of sort of such ordinary, rural simplicity. The idea that it might conceivably contain a spy would be fantastical today and then, even more so. And there was Mrs. Burton. And by day, she was, you know, looking after her children and going to church and cooking her scones and so on, and living the life of a completely ordinary housewife. But in fact, in the outside toilet, in the back garden, she had built a very powerful radio transmitter with which Colonel Ursula Kuczynski of the Red Army was sending the blueprints for the atomic bomb back to Moscow. 

*      *      *

Ursula did not yet realize the historic significance of the information she was passing on to the Centre. But Moscow’s response – enthusiastic, grateful and increasingly demanding – left her in no doubt that she was playing the biggest fish of her career. Soviet military intelligence did not go in for flattery, but the responses to her messages were more effusive than anything she had received before: ‘Important’; ‘Very Valuable’. 

Fuchs’s transfer of scientific secrets to the Soviet Union between 1941 and 1943 was one of the most concentrated spy hauls in history, a step-by-step guide to the fast-moving development of the atomic weapon. 

*      *      *

Klaus Fuchs, the German physicist and communist spy, was able to infiltrate the scientific community in London, and later joined the Manhattan Project in Los Alamos, New Mexico. There he fed atomic secrets to Ursula, who relayed them to Moscow — giving the Soviets a huge boost in the Cold War. In 1951, a U.S. Congressional Committee would conclude that Fuchs had “influenced the safety of more people and accomplished greater damage than any other spy not only in the history of the United States, but in the history of nations.”

LYALL: How would somebody deeply involved in that effort to develop the atomic bomb escape even a light amount of surveillance?  

MACINTYRE: Well, just as I think Ursula’s gender was her best disguise that she ruthlessly exploited to remain invisible, so, I think that Fuchs’s very competence was his best disguise. He was so good at what he was doing. He was so highly valued by the scientists that that was enough to create this disguise. And every so often MI5 would say, “Well, it’s a bit odd because we’re getting hints that he might be a communist.” And the next moment there’s a reference or an encomium from one of his scientific peers saying, “he’s just utterly brilliant. We can’t do this without him.” And so, I think in a way, his very scientific brilliance was his cover. That’s what protected him. 

In 1950, Ursula and her three children flew to Germany. By the time British Intelligence had alerted border patrol, she was already gone. She would not return to England for another forty years.

*      *      *

Ursula’s life had one more surprising chapter. In 1956, she became a full-time writer, adopting yet another name, a new vocation and a fresh identity. Henceforth she would be Ruth Werner, novelist. Ursula had written from earliest childhood, channelling a vivid imagination into her stories of romance and adventure. Spies and novelists are not so very different: each conjures up an imagined world and attempts to lure others into it. Some of the greatest writers of the twentieth century were also spies, including Graham Greene, Somerset Maugham, Ian Fleming and John le Carré. In many ways Ursula’s life had been a fiction, presenting one sort of person to the world, while being someone else in reality. As Ruth Werner she became, once again, another person.  

*      *      *

LYALL: So many Soviet spies who’ve lived much of their career in the West end up in this period back in the Soviet Union or back in East Germany very, very disillusioned with what they find when they get there. They miss the West. They miss the freedom. And they actually start wondering whether it was all worth it, whether their ideological views were actually misplaced in a way, because the life they find is so drab and unpleasant. Did she find that when she got back to East Germany?

MACINTYRE: I think she had sort of swallowed the myth that the Soviet socialist paradise was already being built and that the communist utopia was just around the corner. So, I think initially she was very disappointed, but she sort of stuck to it. She knew that the world isn’t a perfect place. She was, as I say, deeply shocked when she discovered the true nature of Stalinism itself, and the purges, and so on, and when Stalin was denounced by Khrushchev, opening up a whole world that I think she had been genuinely unaware of. I mean, bear in mind, she wasn’t living in Soviet Russia she wasn’t there to experience it firsthand. So, I think she did explore and examine her own communism. And I think by the end of her life, she was disillusioned. I think a lot of what she had believed to be true had turned out to be false, and she was honest enough to say so. 

*      *      *

She was never betrayed. Dozens of people – in Germany, China, Poland, Switzerland and the U.K. – had ample opportunity to expose Ursula, and bring her life and espionage to a swift and unpleasant end. None, save Ollo, ever did. For a diehard communist, she was exceptionally good fun, stylish and warm. She had a gift for friendship, an ability to inspire enduring loyalty, and a willingness to listen and support people whose opinions were radically different from her own. As a revolutionary, she was surprisingly open-minded. She knew how to love and how to be loved. Like all great survivors, she was fantastically lucky.

Ursula Kuczynski died on 7 July 2000, at the age of 93. 

*      *      *

LYALL: You’ve written about how spies are often dishonest by definition. How do you trust that what we’re reading about her and what you’ve read about her is honest?

MACINTYRE: Well, you can’t be absolutely certain. The thing that Ursula and other spies didn’t realize, however, was that classified files, the secret files relating to the way that they were run, would eventually be made public. I had access to all the MI5 files on her. There are 79, believe it or not— 79 different files on different members of the Kuczynski family, including a pretty voluminous set on Ursula herself. They’re accessible in the National Archives just outside London, and anyone can go and see them. And that’s an extraordinary sort of sea change in British official secrecy, because it’s really only quite recently that Britain began to declassify its security service files. And the great thing about those declassified files is that they’re honest in a way that most government files are often not quite honest. And by that, I mean that they are written by and for people who never believed that they would be made public. So, you can actually follow the sort of day-to-day, even hour-to-hour evolution of a case like this written in a way that just lays out the facts, lays out the truth, because you can rely on it because they never thought it would be made public.

LYALL: Ben, thank you so much. This has been absolutely delightful, and I really, really appreciate it. 

MACINTYRE: It’s been a great pleasure. Thank you, Sarah.

*      *      *

The Freakonomics Radio Book Club is produced by Stitcher and Renbud Radio. This episode was produced by Brent Katz. Our staff also includes Alison Craiglow, Greg Rippin, Joel Meyer, Tricia Bobeda, Mary Diduch, Zack Lapinski, Emma Tyrrell, Lyric Bowditch, Jasmin Klinger, Eleanor Osborne, Jacob Clemente, and Ryan Kelley. The audio excerpts of Agent Sonia are courtesy of Penguin Random House Audio; they were read by the author, Ben Macintyre. Our theme song is “Mr. Fortune,” by the Hitchhikers; other music for this episode was composed by Luis Guerra, Michael Reola, and Stephen Ulrich. You can follow The Freakonomics Radio Book Club on Apple Podcasts, Spotify, Stitcher, or wherever you get your podcasts.