Watch the unfriendly skies! It’s just another day in the life of Frank and Joe Hardy, America’s favorite young detectives! In this adventure, the Hardy Boys are hired to go undercover to defeat a gang of vicious airborne thieves. Can the Hardy Boys fly fast enough to save the day? This is a reprint of the 1930 first edition of The Hardy Boys: The Great Airport Mystery, without cuts or censorship, as originally written by Leslie McFarlane under the pen name Franklin W. Dixon.