The Enigma Girls: How Ten Teenagers Broke Ciphers, Kept Secrets, and Helped Win World War II by Candace Fleming

Most kids probably don't know how important secret codes were during World War II. Germans, Japanese, and Allied forces had to send radio messages around the world, and it was vitally important to each side that their messages were not intercepted, and thus each country went to great lengths to disguise their messages and to decode the communications coming from their enemies. This gem of a nonfiction book explains how British citizens spent years of their lives working to break the codes that Germans created using the Enigma machine. The Enigma was a kind of typewriter, but with lots of wheels and almost unlimited combinations of letters that changed daily. The British military took over a large house in the countryside near London called Bletchley Park and they recruited the most brilliant mathematicians and code breakers they could find. They also assigned thousands of young women, many of them still teenagers, to Bletchley Park to help in the work of code breaking. As you will see from this book, those girls did repetitive, very specific jobs day in and day out, never knowing exactly what contributions their work was making to the larger effort of saving lives, stopping the Nazis, and ending the war. 

Candace Fleming has taken this huge topic involving thousands of people, and focused in on 10 teenage girls who left their homes and families to help break the Enigma's codes. The result is this brilliant book, full of flesh and blood young girls away from home, doing important work, while at the same time growing up during wartime. These amazing women went on to live ordinary lives, unable to talk about the work they did for many years (they signed wartime secrecy papers and they all kept their silence). When their stories got out, the world was shocked to discover the brilliant work they did and the lives they saved thanks to their incredible sacrifices. As is frequently the case with Candace Fleming's work, there is much here for teenagers as well as adults. I highly recommend this award-winning book for readers ages 13-up with an interest in World War II, math, secret codes, and women's history.