The night was in one sense a repetition of the preceding one. True, they would not have to consider being halted by a gathering army of the revolutionists, and that was a comfort all around. At the same time Frank deemed it necessary that he and his cousin keep watch. And Andy was perfectly willing to sacrifice some of his personal comfort for the sake of insuring the safety of the precious aeroplane.
It proved just as well that they had so determined. During Frank's second term on guard and somewhere around four o'clock, while darkness covered the land, he thought he caught a glimpse of a shadow crossing the deck, headed in the direction of the lazerette.
He had been lazily reclining on a soft cushion made of several blankets and looking up at the silvery stars, but immediately he became fully aroused. This might mean danger in some shape toward the aeroplane. And no matter, it behooved him to investigate.
So he softly arose to his knees and crept after the shadowy figure.
Cautiously he approached the place where the door belonging to the storeroom was to be found. As he advanced thus he could occasionally catch a peculiar clicking sound, which he believed must be made by some one trying to pick the lock!
The engine of the boat kept up considerable of a racket as it steadily worked along without the dreaded hitch. Besides, there was always more or less splashing of water against the sides, as they pushed against the swift current of the Magdalena. All these things combined to muffle the clicking sound frequently, yet during little lulls Frank could catch it again.
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.