This book read like a page-turning, action-packed thriller and adventure story. But it is all real! Which makes it even better because it is truly unbelievable. Barone writes the different scenes, shared in vignette-type short stories that come together to show a whole picture, in a way that just grabs the reader’s attention and keeps you reading to figure out how everyone comes together to crack the secret code.

World War II had so many complex behind-the-scenes happenings that I am constantly surprised by the pure breadth of the war effort and the means employed to bring an end to it. Unbreakable: The Spies Who Broke the Nazi’s Secret Code by Rebecca E. F. Barone (Henry Holt, 2022) tells the story of the spies, mathematicians, scientists, and naval officers who contributed to breaking “The Enigma” cipher, which proved to be essential to reducing German U-boats in the Pacific.

This young adult nonfiction (also certainly appropriate for adults interested in the subject matter) follows various personalities through the tricks. The Engima was a machine that the German naval leaders and other military personnel used to create coded messages and decode messages. But, despite the best efforts from Polish, French, and British spies, it took many years to determine how codes were created and understood using the mechanical device. Spies in these nations needed confiscated code books to initially understand the messages, and when

Unbreakable roams from the lives of the spies on the continent to the secret British government facilities. There, the world’s top engineers and mathematicians were building the first computers. These computers became essential to the code-breaking efforts as they were run night and day, working to calculate possible solutions for the enigma messages.

So many different nations, specialists, and departments came together in this effort. Sometimes I got confused with the names of so many people. There is a brief guide to the people at the front matter of the book, so that helped. Young adults and adults with a strong interest in math, science, engineering, or WWII history will definitely be fascinated by this tale of intrigue and adventure. Younger children may struggle to keep up with the many people, details, and locations. Based on writing style and reading level, I’d say Unbreakable is for ages 14 and up, although nothing inappropriate (other than war topics, deaths, and difficulties) appears in the book, so interested and able young children shouldn’t hesitate to give a go as well.

I received a digital review copy of this book.

Rebecca Barone gives upper middle grade through adults a comprehensive and well-researched look at code-breaking during World War II, specifically the Enigma machine that stumped the best of the best from the United States, France, Britain, and Poland. The presence of British Alan Turing won’t surprise anyone who is knowledgeable about this aspect of wartime intelligence, but Barone has verified contributions from French Intelligence officer Rodolphe Lemoine, his spy and informant Hans-Thilo
Schmidt from Germany, and Jadwiga Pulluth, a Polish underground member and others. Historical photographs, well-sourced back matter, time line and epilogue giving post-war information on key players is also included. Truly a spectacular book for avid readers of the European theater during World War II. Librarians and care-givers need to think carefully when determining appropriateness for their readers. Text is free of profanity and sexual content and violence is very limited, despite being centered on a death-filled war. However, information on the construction, coding, sequencing, and intelligence aspects of Enigma is detailed and while the chapters are not lengthy, even some readers in grades 8 and up will find it more challenging than they want for recreational reading.

This is a very well researched informative book that will appeal to those wanting to learn more about the subject. It did not hold my attention but I finished it, much like reading an assigned book for a class. Fear it won't find a broad audience.

Riveting, intriguing, fascinating true story of the Enigma, a super complex code encryption machine used by Germany in WWII. Brilliantly researched and written. I’m betting this will win a Sibert medal…

This true story of the WWII code breakers will bring history alive for your middle school and high schoolers. As Hitler terrorized Europe, a group of code breakers, spies, and navy men raced against time to crack the Enigma encryption machine. These brave men and women often found themselves fleeing in the middle of the night in war torn Europe, only to re-establish their work elsewhere and continue cracking the code. As Nazi forces directed their efforts over the radio, a group of highly skilled workers labored over the Enigma, eventually turning the tide on WWII.

Although nonfiction, this book often read like a novel, calling these real heroes to life. There's so much history here that I had no idea about. And the author keep the action going with introducing the reader to a variety of characters all working for the same cause. The book does cover a vast amount of information which can be overwhelming, but I was hooked by the action early on. Unbreakable goes beyond your typical WWII book, taking a look at some of the events in the 1920's & 30's that lead up to this point. Although marketed to middle schoolers, high schooler and adults could easily benefit from the information presented in the book. Author Rebecca E.F. Barone does an amazing job weaving together this great piece of history.

*Disclaimer: I received a free copy of this book from the publisher. All opinions are my own.

With thanks to NetGalley and the publisher for an early copy in return for an honest review.

When I told my brother I was reading this book he immediately responded about Turing's role in breaking the Enigma code. What I really appreciated about the book, and what I think readers will find interesting, is Barone's research that shed light on the large cast of characters that helped break the Enigma code. Typically World War 2 related fiction and nonfiction opens in 1939 or 1940, and I thought the well researched back story from the late 1920's through the 1930's gives readers a fuller picture of what all it took to break the code. Definitely a 4.5 star book to add to your nonfiction classroom library.

Thank you to NetGalley and Henry Holt for a review copy.
Spies, codebreakers and the heroic struggle to defeat the Nazis, animate this well researched account of the decade long struggle to break the German Enigma code. Deciphering Nazi communications was crucial to Allied success and nowhere more important than in defending against the deadly and crippling attacks of the U-Boat wolfpacks. While shortening the war by years and saving countless lives was the successful result, the real Enigma story lies in the fascinating details of dozens of individuals who devoted themselves to subverting and decoding German military communication. Dramatic tales of brave sailors who risked, and lost, their lives retrieving documents from scuttled Nazi ships, the little-known role of Polish cryptographers who were the first to make major breakthroughs, details about Alan Turing and the men and women of Bletchley Park and the hidden histories of the intelligence officers and traitors working inside France and Germany keep the pages turning and create a deep appreciation for the complexity of the story. The level of detail makes Unbreakable best for those with intrinsic interest in espionage, World War 2 or codebreaking. Unfortunately, the cover reads young and may discourage older readers. An excellent epilogue summarizes the impact of breaking Enigma, lets readers know what happened to the Polish, British, French and Germans central to the story, and points out the central role of ciphers in our current online existence. A substantial bibliography and extensive endnotes confirm Barone’s exemplary research.
Barone’s writing is strong and her knowledge of the subject matter is unimpeachable, but in the pre-publication ARC several spelling errors and under-explained asides momentarily derail the narrative. (Why did British Intelligence’s distrust of U.S. Intelligence result in Alan Turing being locked out of his office while on a cooperative mission in the U.S.? Leading a cheer for his scuttled u-boat is the last thing a German captain does, but we never learn how he died, making that detail feel distracting and extraneous. We are told sailors on a German ship about to invade Norway learn from other sailors the horror of rescuing survivors of a shipwreck. It is clear Barone means to imply this information influenced the German captain’s later decision to surrender rather than sink his ship and sacrifice his men, but that connection is never directly made, and with no context the reader is left wondering whether the influential shipwreck and rescue were of Germans, Allies or civilians. During the evacuation of Paris people “floo chaos”. German crewmen on the weathership Lauenberg “had been stayed behind”. Arriving in England the Polish cryptographers are described as “Thevery geniuses”. And the grammatically odd formulation of the “thousand little decisions sum to destiny” undercuts a grand sentiment.

Barone has done an exquisite and exhaustive job at tracking down a huge number of figures involved with the cracking of the Enigma machine's codes, and presents this information in vignettes that capture the suspense and danger these brave men and women would have felt. It's a page turner, but does cover such a vast amount of information that I just couldn't keep it all straight. This will not bother my readers, who seem to have the entire timeline of the war memorizes and don't have any trouble getting through Weintraub's No Better Friend: Young Readers Edition: A Man, a Dog, and Their Incredible True Story of Friendship and Survival in World War II or Farrell's Pure Grit. I will definitely purchase this, and it will circulate really well, given the fantastic cover.

As a fan of Barone’s debut “Race to the Bottom of the Earth: Surviving Antarctica” I was excited to see this WWII nonfiction novel. My middle school students are wild about anything and everything WWII and I’m sure this will be no exception. The writing presents background information, an explanation of the enigma machine, and clearly defined key players. Sources are cited at the end for further reading.

Thank you to NetGalley and Henry Holt for the advanced reader's copy of this incredible book. Unbreakable: The Spies Who Cracked the Nazis' Secret Code is a work of narrative non-fiction that reads like a spy thriller. I can see many of my reluctant readers being quickly hooked by the details and tense moments in the text, especially since so many chapters end with a cliffhanger. Rebecca Barone is a talented writer who gives enough detail to drive to narrative but not so many details that the text becomes dense and boring. She also includes incredible primary source images and documents to help the reader better understand what they are reading. As a history teacher I was overjoyed to see Barone's extensive bibliography at the end of the book to provide additional resources for both students and educators. I thoroughly enjoyed this book and read it in two sittings. I was hooked!

This is a very good book! It is well written and provides such wonderful information! I will definitely be adding a copy to my classroom library for students.

Thank you to #NetGalley and #henryholtandcompany for an eARC of UNBREAKABLE: THE SPIES WHO CRACKED THE NAZIS’ SECRET CODE by Rebecca E.F. Barone (Release Date: October 25/22).

This author’s nonfiction debut, RACE TO THE BOTTOM OF THE EARTH: SURVIVING ANTARCTICA, has stuck with me since I read it at the beginning of last year, so I was thrilled to get an eARC of her upcoming book. I love reading middle-grade nonfiction, but finding a length and subject matter that will hook a young reader is tricky. This book does just that with a length of only 272 pages (including back matter and over 60 historical photos) and a fascinating look at the codebreakers who raced to figure out how to decode messages sent by the Enigma machine used by the Nazis in World War II. Individuals in many European Allied countries worked to piece together bits of stolen information to uncover the Nazis’ plans, some while escaping the violence in their home country. Still, it took many years and countless hours to figure out how the Enigma machine worked, and this book gives an in-depth look at some of the key players. I will definitely be purchasing this book for my library’s collection and recommend it to readers who like BOMB by Steve Sheinkin.