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.
He evidently chose to take chances in the swift current of the Magdalena rather than trust himself in the power of the unknown pursuer, which doubtless he believed to be the dreaded "devil-bird" that had been confined in the box cage!