ISBN-13: 9781618212504 / Angielski / Miękka / 2014 / 128 str.
The Pig Pen Cipher, the Devil's Coffee Mill, and germ warfare were all a part of the Civil War, but you won't learn that in your history books Discover the truth about Widow Greenhow's spy ring, how soldiers stole a locomotive, and the identity of the mysterious "Gray Ghost." Then build a model submarine and send secret light signals to your friends. It's all part of the true stories from the Top Secret Files of History. Take a look if you dare, but be careful Some secrets are meant to stay hidden...