Nathalia Holt: What drew you to this story?

Jason Fagone: Well, it’s one of these amazing American origin stories. A hundred years ago, a young woman in her early twenties suddenly became one of the greatest codebreakers in the country. She taught herself how to solve secret messages without knowing the key. Even though she started out as a poet, not a mathematician, she turned out to be a genius at solving these very difficult puzzles, and her solutions ended up changing the 20th century. She helped us win the world wars. And she also shaped the intelligence community as we know it today.

NH: William Friedman has long been recognized as a pioneer of cryptology, so why have we never heard of Elizebeth before?

JF: Sexism and secrecy. A lot of the time she was omitted or even erased from the records by the men in her life. Sometimes they were men close to her, like her husband, William Friedman, who was also a champion codebreaker, and sometimes they were men in power, like J. Edgar Hoover. All through World War II she used her skills to hunt Nazi spies who were spreading into the West. She broke these Nazi spy codes for the FBI, which would have been lost without her—and then Hoover turned around and painted himself as the big hero. There was nothing she could do, because of secrecy rules.

NH: In the Author’s Note of your book you describe the excitement of discovering Elizebeth’s archives in a vault of a Virginia library. What was that moment like and what types of resources did you use to research this story?

JF: I’ll never forget that moment. Elizebeth donated 22 boxes of papers to the George C. Marshall Foundation in Lexington, Virginia. Since her death in 1980 those boxes have been carefully preserved at the Foundation’s library in a vault. Elizebeth left thousands of her personal letters, whole diaries full of poems, newspaper clippings of her famous rum cases, and original code worksheets. She kept everything that wasn’t classified. The only period of her life missing from the archive was 1939 through 1945—World War II. So I had to patch the gap. It took me more than two years to find the missing records, hunting through archives in the U.S. and the U.K.

NH: How can Elizebeth Smith Friedman’s story inspire young women today?

JF: I think a lot of professional women today can relate to her experiences. She did all this important work and got very little credit. But at the same time, because she was so good at her job, she had a lasting impact on the world. She blazed a trail in a lot of ways, and she did it in her own style. Once she wrote, “If I may capture a goodly number of your messages, even though I have never seen your code book, I may still read your thoughts.” That captures her personality: Do whatever you like, but I still have this mind, and you will have to reckon with it.

NH: This book is in many ways a love story. Can you tell us about the letters sent between Elizebeth and her husband?

JF: Elizebeth and William started writing to each other before they were romantically involved, when they were still only friends. They were these two young people who wanted to accomplish great things, to leave a mark. In 1918, when William joined the Army and sailed to France to serve as a codebreaker, he wrote Elizebeth these 20- and 30-page love letters by the light of an oil lamp, calling her 'Divine Fire.' He liked to include bits of code that he knew only Elizebeth would understand, and she replied in code, too. For the Friedmans it was a lovers’ shorthand, a way of staying connected. And later, when they had kids, they taught the kids how to do it, too.

Nathalia Holt is the New York Times bestselling author of Rise of the Rocket Girls: The Women Who Propelled Us from Missiles to the Moon to Mars and Cured: The People who Defeated HIV.