The narrative follows a group of Boy Scouts who spend their summer learning about aviation at a newly opened airfield, practicing flying skills, and assisting the field manager. Their curiosity leads them into a series of linked incidents—a local mystery, secret clues, explorations of a cave, and the discovery of a man held captive—that require teamwork, daring, and quick thinking. The plot builds to a dramatic aerial confrontation and nighttime encounters, after which the scouts must decide how to handle a monetary reward and the consequences of their actions. Themes include friendship, practical skill, courage, and responsible citizenship.