None of them cared to remain up any longer. The skipper made his appearance just then, and announced that he would see to it that a guard was posted on the upper deck, and armed in the bargain.
“It may be those sharks won’t think to try and do us any harm while we’re here in the canal,” he went on to say dubiously, “because it might be like killing the goose that lays the golden eggs; for their only hope seems to be to chase around after us, and try to swoop down on something we’ve found. But I’m taking no chances. You see, I know Badger too well to trust him one minute. He’s well named, though Weasel might fit him even better.”
Going below Oscar and his two chums soon made themselves comfortable in their several bunks. As the hatch in the conning tower was open, and the ventilators doing their regular work in addition, it seemed much more comfortable down below than ordinary, for the weather was excessively warm during the days.
Oscar remembered lying there for a little while, thinking of things in the past; but he finally went to sleep. The other pair were already far in dreamland, as their regular breathing attested.
When Oscar awakened he could not tell why it was he seemed to feel a strange sensation, just as though some deadly peril hovered over them. A slight sound drew his attention, and turning his head on his pillow he saw something that caused him to hold his breath with amazement.
There was always a dim light left in the apartment the boys occupied, which, in fact, bordered the little den Captain Shooks dignified by the name of “office.” Where he lay Oscar could look straight through the open doorway, and see the whole interior of this “cubby-hole,” as Ballyhoo always called it.
Some one was stooping over in front of the desk at which the skipper so often sat when writing up his papers, and entering events in his log of the cruise. Oscar saw to his dismay that it was not Captain Shooks, but an utter stranger, a small, wiry fellow, who had managed in some mysterious way to get inside the submarine. Instantly Oscar suspected that the sailor they had left in charge of the upper deck while they went ashore must have been unfaithful to his duty, and left the hatch unguarded for a few minutes while he crept below, possibly to get his pipe.
It did not matter so much how the spy had managed to get aboard as that he was searching eagerly through the skipper’s private papers, evidently looking for the priceless chart that told, as near as was known, the exact location of a dozen other sunken treasure ships, besides the two already visited.
Oscar could not hold in any longer. Giving a shout he sprang from his bunk, and made a swift lunge toward the door of the office, intending to close this, and keep the intruder shut in until the skipper could attend to him.
Unfortunately, Oscar caught his foot in some object that may have been purposely placed there with the intention of tripping any of the sleepers should they awaken while the spy was at work.