From breaking enemy agents' ciphers to translating long lost languages, help solve all kinds of secret codes and mysterious messages in this exciting book, which is packed with over 100 puzzles. With safe combinations to crack, computer systems to hack, and much more, there's plenty to keep young codebreakers busy on journeys, rainy days and holidays.
ThriftBooks sells millions of used books at the lowest everyday prices. We personally assess every book's quality and offer rare, out-of-print treasures. We deliver the joy of reading in recyclable packaging with free standard shipping on US orders over $15. ThriftBooks.com. Read more. Spend less.