The Bletchley Riddle * Ruta Sepetys, Steve Sheinkin

Remember, you are bound by the Official Secrets Act…

Summer, 1940. Nineteen-year-old Jakob Novis and his quirky younger sister Lizzie share a love of riddles and puzzles. And now they’re living inside of one. The quarrelsome siblings find themselves amidst one of the greatest secrets of World War II, Britain’s eccentric codebreaking factory at Bletchley Park. As Jakob joins Bletchley’s top minds to crack the Nazi's Enigma cipher, fourteen-year-old Lizzie embarks on a mission to solve the mysterious disappearance of their mother.

The Battle of Britain rages and Hitler’s invasion creeps closer. And at the same time, baffling messages and codes arrive on their doorstep while a menacing inspector lurks outside the gates of the Bletchley mansion. Are the messages truly for them, or are they a trap? Could the riddles of Enigma and their mother's disappearance be somehow connected? Jakob and Lizzie must find a way to work together as they race to decipher clues which unravel a shocking puzzle that presents the ultimate challenge: How long must a secret be kept?

Perfect For: Devotees of traditional, fast-reading World War II espionage thrillers and historical mysteries like The Imitation Game or Alan Gratz's Allies; educators looking for meticulously researched middle grades and young adult literature highlighting codebreaking logistics and computing history; and dedicated book collectors maintaining a complete shelf of the globally bestselling Ruta Sepetys historical fiction bibliography.

Pennsylvania Young Readers' Choice Award Nominee for Young Adult (2026), Vermont Golden Dome Book Award Nominee (2026), CYBILS Award Nominee for Elementary/Middle Grade Fiction (2024), Volunteer State Book Award Nominee for Middle School (2026), Massachusetts Teen Choice Book Award Nominee (2025)

Published 2025 by Viking Books for Young Readers, stated 1st Printing