Want to learn how to make and break TOP SECRET messages like a real spy? If so, this book is for you! In this exciting, award-winning nonfiction companion to the debut series SECRET AGENTS JACK AND MAX STALWART, readers ages 8 - 12 years old can learn behind-the-scenes codebreaking and spy skills. Inside are more than 80 pages of tips, tricks, and practice exercises for writing and deciphering cryptic communications. You'll learn how to make your own invisible ink, hide your messages, create unbreakable ciphers, and craft your own decoder gadgets. You can use this manual to learn how to exchange top secret notes with friends. Expanded and republished!