Want to know what invisible ink has to do with the American Revolution? Or why shark repellant and inflatable army tanks were used in World War II? Find out in this fact-filled series of fascinating true tales, wild adventures, and spy missions, and discover the secret side of American history! An extend-the-learning section at the back of the book covers the ocean's food chain, how area is calculated, and more!.

World War II begins -- Cooking up shark repellent -- The ghost army with the inflatable tanks -- The allies' most dangerous spy.