The author's upbeat, positive tone is refreshing and his enthusiasm about his topic is contagious. -- School Library Journal (starred review)Pssst! Do you know the difference between a code and a cipher? Can you tell a St. Cyr slide from a Cardano grille? Did you know that the discovery of a substitution cipher caused Mary Queen of Scots to lose her head? Don't look now, but packed into this practical field guide is everything a young person needs to know about the art of concealment -- making and breaking codes, mastering cipher systems, and experimenting with secret writing. Offering plenty of hands-on practice sessions, tips for creating a code-making kit, sidebars on secret codes in history, and an amusing pair of spies to illustrate techniques, Paul B. Janeczko's tantalizing Top Secret won't stay a secret for long. Back matter includes suggestions for further reading, an author's note, an answer key, and an index.