Particularly did Blaine distinguish himself in the daring of his stunts. Erwin was hardly behind him. They looped again, they rolled, they did the wing and tail slides, doing the last until they fell almost perpendicularly a thousand feet. Finally they righted hardly two hundred feet above the earth; then shot upward again at almost incredible speed. And now the two leaders circled slowly as their respective squads followed on towards the ground, some falling, drifting like dead leaves, others slanting lazily as they passed the leaders, and on down, alighting at last each in his appointed place or thereabouts. And then the two leaders began circling and swooping more and more rapidly until those below felt the whirring rush of air as the two planes swept by so low that one imagined that an arm would nearly touch them. All hands knew it was rivalry -- the rivalry of stunts. Yet to stand below and watch those steel engines falling down on you from the skies took the same kind of nerve to keep from dodging as only airmen themselves are gifted with by practice. Finally all this drew to a close. The machines at last ranged themselves at opposite extremes of the landing stage and with a final swoop both were apparently upon the spectators as with the rush of a whirlwind. Yet, dizzy as it looked, it was mathematically timed. The two planes flattened as if by magic; they rose, dipped again and, passing each other in the down grade, saluted methodically as they passed the Commander. Ten seconds later their wheels dropped gently on the gravel at either end of the parade ground two tired looking aviators left their the waiting mechanics and walked soberly to the others. The stunts were over for the day. CHAPTER VI CATCHING THB SPY "Well, well, Orry! How do you feel after your stunts of yesterday?" This from Sergeant Blaine as he jumped from his bunk in the aerodrome dormitory the following morning just as the dawn was breaking. Erwin, still drowsing, opened one eye. The next instant, remembering what the day probably hold in store for him, he threw off the covers and leapt from his bunk. At the same time, in order impress Blaine with his general fitness, he hit the big Sergeant a mock blow on the midwind region where, according to ring history, Fitzsimons dropped Corbett in their historic championship fight. Then he sprang back, arms and fists feinting. "Can't you see how I feel?" he retorted. "Want to try me more?" "Nit, you shyster, nit!" Blaine was laughing as he recovered, retreating and grimacing, as if in mock misery. "I don't want no more solar plexus stuff at this stage of the game. I guess you're all right." "Bet your thick cocoanut I am! I was a bit drowsy at first. Say, Lafe, you know I must be in on this, whatever it is." "Sure! I was at first a bit afraid that all those air stunts might have frazzled you a little, seeing you are just out of hospital."