The secret’s out: two heavy-hitters in the realm of children’s historical fiction and nonfiction, Carnegie Medalist Ruta Sepetys and Newbery Honor-winning author Steve Sheinkin, have joined forces for a new middle grade adventure blending history and mystery. The Bletchley Riddle is set in the summer of 1940 at Bletchley Park in England, nerve center for the highly classified work of the Allied codebreakers of WWII. The book is due October 8 from Viking Books for Young Readers, with an announced first printing of 250,000 copies. The cover, designed and illustrated by Jim Tierney, is revealed here for the first time.

Prior to teaming up as co-authors, Sepetys and Sheinkin had been friends through the conference circuit and long admired each other’s work. They can pinpoint the exact time and place that the idea for a joint project first sparked. In 2019, they participated in a panel in New Orleans, hosted by reading specialists and bloggers Erin O’Leary and Mary Varney Cotillo, aka the Crazy Reading Ladies. When asked “if you were ever to collaborate on a book, who would be your dream co-writer?,” Sepetys said, “I literally looked down the panel and pointed at Steve.” The rest, as they say, is history—or, in this case, historical fiction.

Describing the brainstorming process that led them to their novel, Sheinkin said, “At first, the sort of logical idea was we would pick something, a moment in history. Ruta would do a fictional treatment of it, and I would do more nonfiction—so basically, what we’ve each been doing for the last 15–20 years.” But after further reflection, the duo landed on a more unified approach. “We thought, wouldn’t it be more ambitious and exciting to come up with one story and find a way to tell it together?”

During the pandemic, the authors began discussing the book in earnest, sharing a list of possible topics via email, with Sheinkin at his home in Saratoga Springs, N.Y., and Sepetys in Nashville. For many years, Sheinkin had kept Bletchley in his internal “history nerd” file, thinking, “Maybe I’ll write about this one day.” He said, “I’ve also been long obsessed with codes and codebreaking. And so I was thinking, ‘Is there a book there?,’ and I was just so happy when I threw that idea out there and it grabbed Ruta’s imagination, too.”

Sepetys recalled the lightbulb moment as well. “I will not forget when he brought up the idea of writing something that had to do with codebreaking and set at Bletchley Park, which, of course, is such a rich atmosphere,” she said. “Even though I did know of the important role that Bletchley played in shortening the duration of the war, Steve mentioned a hidden history element, which I had been unfamiliar with. As soon as he shared that, I said, ‘That’s it.’ ”

Cracking the Code

Sepetys described the resulting story as “Enola Holmes meets WWII.” The novel follows 19-year-old Jakob Novis, a member of the elite team of codebreakers at Bletchley Park that is urgently trying to crack the Nazi’s Enigma cipher, and his younger sister, Lizzie, who is 14. Meanwhile, Lizzie is determined to solve the mystery behind their mother’s disappearance. Could the two be connected?

Like their teen characters, the authors brought their own investigative skills to the assignment. “I’m just a collector of stuff. And you can sort of see a little bit here. You can’t see the floor, which is the really messy part,” Sheinkin said, gesturing via Zoom to the cozy disarray of his office. “I buy tons of used books and love to read old newspapers.” Due to the Official Secrets Act, which kept the existence and inner workings of Bletchley under tight wraps both during and after the war, he said, “Of course, nothing about Bletchley would have been in the newspaper for decades. But I read as much as I could to start with, because I didn’t know exactly what I needed to know.”

It was this shroud of mystery that drew Sepetys to the subject. “Something that really intrigued me was the aspect of secrecy, and how long these people who had given years to such an enormous undertaking didn’t tell anyone, not even their spouses.”

Middle grade turned out to be a natural fit for the story. Sheinkin pointed out, “There really were a lot of young people who were instrumental at Bletchley Park, including teenagers, as messengers and even codebreakers. We wanted to explain how it worked and what they did.”

Sepetys said she had always envisioned the book as middle grade. “There’s this sense of enchantment,” she said. “And there were some eccentric details that I just love, of the cast of characters and how they assembled and chose the people to create this code-breaking factory.” Having previously written YA, she welcomed the shift to middle grade. “It was wonderfully freeing,” she reflected, “in that so many of the topics I’ve written about not only involve hidden history, but violence, or brutality, oppression, and systems of power that are quite intense. Mind you, this is set during the Battle of Britain, and it was absolutely intense. But it was a more imaginative take for me, and it was absolutely delightful.”

The pair’s research brought them across the pond to the Bletchley Park headquarters. “Ruta said early on that it was almost Wonka-like inside the gates of this rural estate,” Sheinkin said. “It looks very much like the pictures from the ’40s. And there is something Wonka-like about it that just appeals to the imagination of grown-up kids like us.

Fictionalized versions of Bletchley Park have appeared on the screen in recent years, including in the 2014 film The Imitation Game and the 2012–2014 television miniseries The Bletchley Circle, but Sheinkin felt that the codebreaking process “was so frustratingly oversimplified. As a viewer, I wished they could have tried a little bit harder to explain how incredible it was, technically, what they did, and how they did it. So, I wanted that to be a piece of research. I felt like that was actually part of my assignment: to try to really understand—not in the way Alan Turing would, because that’s impossible—but in the way I could.”

Sepetys likened their writing method to a kind of codebreaking. “Steve has a very defined process that works. At the end, his practice is to tear things down and take it all apart! And even though there were times that I couldn’t see exactly where this was going, he knew and could help direct us. And you know, the same applied to codebreaking.”

Each took on the perspective of one of the protagonists, she explained. “Steve really had the herculean task: he was writing the code-breaker character. I was writing the little sister. He had to convey to the readers the scope of what they were trying to achieve in the war and breaking the Enigma code, which was really complex. And he did it in such an amazing, engaging way.”

Kelsey Murphy, senior editor at Viking, said, “It has been an absolute joy watching Ruta and Steve collaborate to bring this incredible story to light. And readers couldn’t be in better hands, as they are both absolute experts in their field, so well-researched and precise, enthusiastic, inventive, and surprising with every choice they make.”

Going Undercover

The final piece of the puzzle was the cover art. Sepetys said, “When Kelsey sent us the name of the designer, Jim Tierney, and his website, we thought, absolutely. We did see a few different designs, but this one I felt really captured the story.” The illustration centers a figure on a motorbike, silhouetted against a glowing sky with warplanes overhead and lines of code woven throughout. “It has motion to it and all the elements: it’s the war, it’s codebreaking, it’s a story of young people. I just loved it,” she said.

Sheinkin agreed, saying, “I think it does a really good job of visually getting across the excitement and adventure and codes and mystery.” As for the content between the book’s covers, Setepys said, “We asked ourselves, what types of books delighted us as kids? And that inspired us to layer in some secrets. They might not be readily evident on the first read, but we both know from doing so many school visits there are young readers who really do read between the lines, and hunt and peck and search, and we’ve layered in some surprises and Easter eggs for them.”

She expressed gratitude for the other historical investigators who helped light the way. “Steve and I greatly benefited from all of the research that has been done on Bletchley; our book sits on the shoulders of the work that came before us.” She also credited research historian David Kenyon for spending time with them at Bletchley. “Imagine the gift of being able to sit down with him and peel back all those layers, literally, in the mansion itself, on-site at Bletchley Park. That was very special.”

Sheinkin said, “Every time we talk about the book, we get excited again.” He stressed the importance of inviting children to wonder about the past. “Something that captivates the young reader and makes them want to turn the pages is so valuable. That, to me, is the most important goal. And that’s the beauty of really diving into history: that it sparks the individual’s curiosity about something. And that will always be relevant to what’s going on in their lives and the world today.”

Echoing his sentiment, Sepetys added, “I hope the book engages readers to understand what a treasure trove the history of Bletchley Park is, and all of the human beings who gave their time and their energy and their intelligence to that effort.” She concluded with a promise. “There are so many more secrets to uncover and discover.”

The Bletchley Riddle by Ruta Sepetys and Steve Sheinkin. Viking, $18.99 Oct. 8 ISBN 978-0-593-52754-2