CONTENTS
Chapter
[I]—THE BOY FLIERS
[II]—ON GUARD
[III]—NOT CAUGHT NAPPING
[IV]—THE STARTLING NEWS
[V]—THE EXCITEMENT GROWS
[VI]—FIGURING IT ALL OUT
[VII]—THE AIR SCOUTS
[VIII]—JUST BELOW THE CLOUDS
[IX]—THE PILOT OF THE MERMAID
[X]—HEARD OVER THE WIRE
[XI]—COMPARING NOTES
[XII]—AT THE HOSKINS FARM
[XIII]—THE BUTTERFLY COLLECTOR
[XIV]—A CLUE
[XV]—WHEN CASPER CAME BACK
[XVI]—THROWING OFF THE MASK
[XVII]—SALLIE RIDES BAREBACK
[XVIII]—AN AEROPLANE CHASE
[XIX]—DROPPING A "BOMB!"
[XX]—OVER LAND AND SEA
[XXI]—OVER THE BOUNDARY LINE
[XXII]—THE HYDROPLANE RESCUE
[XXIII]—BROUGHT TO BOOK—CONCLUSION