"Garbo: The Spy Who Saved D-Day" is a hardback book from the "Secret History Files" series, published in 2001 by National Archives (Pro) and T.H.E. The book, authored by Mark Seaman, delves into the secret history surrounding the D-Day invasion, focusing on the role of a spy named Garbo. With a mix of artistic styles from various artists and a total of 384 pages, this book is a detailed and informative read on a pivotal event in World War II history.