The Mystery Of The Flying Express, The Hardy Boys Mystery Stories. Author: Franklin W. Dixon. 217 pages. Hardcover book, no dust jacket. Publisher: Grosset & Dunlap, 1941.

This is the original version of this title and features the Hardy boys on a mission assigned by their detective dad. They travel west to locate a hidden spy training camp used by a foreign power and uncover a network using a daily passenger train, the Flying Express, to transmit secret messages. 

The book is in good to good plus condition. The book has a small tear on the cover at the top of the spine with a small 1/4" piece missing (see photos). The binding is good and there are no loose or torn pages. The interior pages are in very good condition. There is a name written on the inside of the cover page. No dust jacket.