The Unbreakable Code

by Jennifer Chambliss Bertman with illustrations by Sarah Watts
Published by Christy Ottaviano Books / Henry Holt and Company
ISBN: 978-1-62779-116-8

Mr. Quisling is definitely up to something mysterious, and Emily and James are on high alert. First, there’s the coded note he drops at a book event. Then, they uncover a trail of encrypted messages in Mark Twain-penned books hidden through Book Scavenger. What’s most suspicious is that each hidden book triggers an arson fire.

As the sleuthing friends dig deeper, they discover Mr. Quisling has been hunting a legendary historical puzzle: the Unbreakable Code. This new mystery is irresistible, but Emily and James can’t ignore the signs that Mr. Quisling might be the arsonist.

The clock is ticking as the arson fires multiply, and Emily and James race to crack the code of a lifetime.

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Buy Book Scavenger
  • Debuted at #6 on the New York Times Bestseller list!
  • Junior Library Guild selection, Spring 2017
  • California John and Patricia Beatty Award Nominee, 2018
  • Translation rights sold in twelve languages/countries: French, Spanish, Catalan, German, Czech, Polish, Chinese (Simplified and Complex), Russian, Korean, Romanian, and Turkish


“Readers who loved the first volume will find this follow-up even more satisfying. Purchase extra copies where there are fans. –Katya Schapiro, Brooklyn Public Library”

School Library Journal

“Making extensive use of San Francisco history and locales, Bertman offers another involving chapter book in the Book Scavenger series, which offers a large, interesting cast of characters, plenty of challenges for code enthusiasts, and more complexity than most middle-grade mysteries. The appended author’s note helps readers separate fact from fiction. Young readers captivated by these distinctive characters will be hoping for the series to continue.

— Carolyn Phelan” —Booklist

“Brisk, bookish good fun for puzzle and code lovers.”