A fascinating look at history's most mysterious messages, packed with puzzles to decode and ciphers that children can use themselves. Includes the encrypted notes of Spartan warriors, the brilliant code-crackers of Elizabeth I, secret messages of the American revolution, spy books from the Civil War, the famous Enigma machine and the Navajo code talkers. As computers change the way people communicate, codes today are more intriguing than ever. From invisible ink to the CIA, this exciting trip through history is a hands-on, interactive experience.