CONTENTS
[I “Suspicious Sandy”] 5 [II Ghosts, Gum—and Gems] 13 [III The Sky Patrol Organizes] 21 [IV Mystery Over the Ocean] 30 [V Mystery in the Fog] 42 [VI The End of the Chase] 50 [VII The Swamp Gives Up a Clue] 54 [VIII Sandy Meets a “Suspect”] 64 [IX Jeff Encounters a “Jinx”] 73 [X Larry’s Capture] 82 [XI “Pop! Goes Our Mystery!”] 95 [XII The Hoodooed Airplane] 103 [XIII The “Hoodoo” Strikes] 112 [XIV Dick Handles a Control Job] 121 [XV A Trap is Baited] 131 [XVI The “Bait” Vanishes] 139 [XVII A Fight for a Fortune] 146 [XVIII Outwitted!] 155 [XIX A Baffling Discovery] 160 [XX Sandy Turns Over a New Leaf] 168 [XXI The Sky Patrol Gives Up] 176 [XXII The “Ground Crew” Takes Hold] 182 [XXIII Larry “Solos”] 190 [XXIV A Puzzling Development] 196 [XXV High Wings!] 204 [XXVI The Race] 212 [XXVII Sandy’s Discovery] 220 [XXVIII Night in the Hangar] 228 [XXIX Sandy’s Trail] 239 [XXX Dick Encounters the “Ghost”] 245 [XXXI A Triumph for the Enemy] 250 [XXXII A Double Pursuit] 255 [XXXIII A Battle Above the Clouds] 263 [XXXIV The Emeralds Are Found] 270