Publisher's Synopsis
In this title, readers will learn how spies used covert communication techniques such as secret codes, invisible ink, and tiny cameras to pass intelligence to their handlers. Real-life spies and missions are explored. Readers can also try making their own invisible ink, dead drops, and secret codes. Aligned to Common Core Standards and correlated to state standards. Abdo & Daughters is an imprint of Abdo Publishing, a division of ABDO.
