The boys were in the conning tower by the conclusion of Mr. Barr's words. The barograph showed them to be rising a hundred feet a minute. No words were exchanged between the two young Scouts, but each grasped the other's hand in a firm grip and gazed into the other's eyes. There was no necessity of speech. Both realized that they had passed through the gravest peril that even they had experienced in all their adventurous lives. When the _Peacemaker_ reached the surface once more, the storm had subsided. With their hearts full of deep gratitude for the miraculous chance that had saved their lives, her occupants headed the speedy diving craft back for the island at top speed. The _Peacemaker_ had been through the supreme test and had not been found lacking. "I tell you what, Barr," declared Ensign Hargreaves, as they neared the familiar island, "you have the most wonderful boat on earth, and Uncle Sam has _got_ to have it. My report goes in to Washington to-morrow and you can guess what it will contain." "Thank you," said the inventor simply, extending his hand. CHAPTER XXIX. INTO THE JAWS OF DEATH. "That's queer, Rob!" "What's queer, Merritt, the way you've been sitting and staring for the last ten minutes?" "No; that odd noise. Don't you hear it?" The two lads were seated in the cabin of the submarine on "night guard duty," as it was called. Following the anxious days when Berghoff had made affairs on the island so filled with uneasiness for the Scouts and their friends, this sentry duty had been regularly maintained. On this particular night the task had fallen to Rob and Merritt. There was nothing very arduous about it, the only duty involved being to keep ears and eyes open. Both lads had been engrossed in books dealing with their favorite subjects when Merritt called Rob's attention to the odd sound he had noticed. "Maybe my ears are not quite so sharp as yours, old boy," said Rob, after an interval of listening. "I've got a slight cold, anyhow, and perhaps that's why I don't hear so readily." "Possibly so." "You are sure you weren't mistaken?" "Think I'm hearing things?" indignantly responded Merritt. "No, siree, I'm willing to bet. Hark! There it is again!" "By Hookey! I heard it that time, too. What can it be?" "Hush!" The noise was a most peculiar one. It seemed to be a sort of scraping on the outside of the submarine's hull. The diving craft was anchored at some distance from the shore, so as to be more readily prepared for a projected run the following day. This made the noise all the more inexplicable, as, had the craft been in the shed, it might have been caused by the inventor or the ensign paying a night visit to see that all was well, which they sometimes did. "Perhaps it's a log bumping against the side." "No; it appears to come from under the water." "That's so," agreed Rob; "tell you what, Merritt, it's up to us to investigate." "Yes, let's go on deck and see what we can find out."