The tumult also served to deaden any shuffling he may have made while creeping toward the lazerette door, and for this Frank was thankful.

It was very gloomy here.  A hanging lantern some distance away only served to accentuate the gloom apparently.  Still, by straining his eyes, Frank believed he could just manage to make out a stooping figure at the door.  Yes, he was certain that it had just moved, and now the peculiar clicking was much plainer.

When it stopped he remained perfectly motionless, nor did he again commence his creeping forward progress until it started once more.

Frank no longer had the slightest doubt concerning the cause of that suspicious clicking.  One of the crew was endeavoring to force an entrance into the locked lazerette, doubtless with the intention of destroying the valuable aeroplane.  He might be in league with the revolutionists and in this way hoped to prevent the government from eventually securing possession of the machine which would put the insurrectos out of the running.

But Frank had conceived another idea.  He now believed that his fellow might have been sent by the crew to destroy the “devil-bird,” as they undoubtedly considered a contraption that could soar through space as fast as the fleetest condor.

No matter.  It was his business to put a sudden stop to the action.  And while doing so he must not be too rough in his dealing with the fellow, lest the entire crew rise in revolt.

When he had reached a point that allowed of a leap, Frank suddenly sprang forward.  He did not know just what he might be up against and had even taken from his pocket the splendid new pistol which Colonel Josiah, himself a world traveler, had insisted upon giving each of his boys before they started on their trip south.

“Surrender!” cried Frank, believing that the very sound of his voice would do much toward frightening the would-be traitor.

But he hardly expected such a tremendous upheaval as followed.  The man, believing that possibly the “devil-bird” had broken out of its cage and was about to carry him off in its gigantic beak, gave a shrill scream of terror, and bouncing up, broke the slender hold Frank had secured upon his person.

Not to be outdone, Frank, recovering, chased after him.  He believed it his duty to at least learn the identity of the rogue, so that he might understand just how deeply the conspiracy had taken root in the crew.

Between himself and the hanging lantern he could make out the fleeing figure of the fellow, and hot in pursuit he followed as fast as his feet would let him.  The man undoubtedly heard him coming, for, if anything, his fright increased.  Out upon the open deck they flew, Frank just a few feet in the rear.  He had even stretched out his arm and touched the garments of the runner, when with a screech the fellow made a furious plunge straight over the side of the boat.