CHAPTER I.
SAVED BY QUICK WIT.
"Hold on there, I want a word with you!"
Billy Barry and Henri Trouville, the Boy Aviators, were in the act of climbing into a superb military biplane on the great parade ground at Hamburg when thus hailed by a mild looking man in citizen's attire, with face half-hidden by a slouch hat and a pair of huge, horn-rimmed spectacles.
There was a note of authority in that voice, gently tuned as it was, and behind those spectacles were a pair of eyes as keen as gimlet points.
The speaker was none other than Roque, the noted secret agent—"Herr Roque," if you please, fitting into his masquerade as a merchant having contract business with the authorities of the canvas city of aëroplane hangars.
"Come over to quarters for a few moments, young sirs, won't you?"
The polite manner of request was for the benefit of the bystanders, who had been awaiting the flying exhibit, but the slight gesture that went with the words indicated a command to Billy and Henri.
They knew Roque!
Heinrich Hume, aviation lieutenant, who usually had a good deal to say on those grounds, made no more protest than a clam at this interruption of a special aëroplane test. He simply waved two other aviators on duty into the machine, as Billy and Henri marched meekly away with the imitation merchant.
While many of the spectators marveled at the apparent breach of discipline, the lieutenant was content to let them wonder. At least, he offered no explanation.