The thrills of flying and sleuthing are combined in the stimulating occupation of Ev Kris, aviation detective. Sought by public and private organizations alike, each of Ev's assignments forms a separate story with danger and adventure the common ingredients. In one case, his investigations of a field dusting operation reveal a criminal saboteur, in another, his position in the sky points the finger at an elusive criminal. More serious missions include work for the F.B.I. and Air Force and surround the hero with those qualities and situations that always appeal to boys.