Unable to find any trace of them, the boys were placed in the position of not knowing whether Jasper had been taken or not. The going became so difficult, and the hope of reward so slight, that in the end they determined it would be best to also leave the river, and take to the higher ground. Here they could wander about, constantly on the watch for some sign that would indicate a temporary camping place of those whom they sought. If a wisp of trailing smoke caught their attention it would do much to locate the resting place of the Indians. They must eat, and particularly the Frenchmen would desire a warm meal, so that in this way those who sought them might be rewarded for their vigilance. Hope was struggling with despair in Roger's heart. Look as he might, he could not see any silver lining to the dark cloud. Still, the energy and resolution that his companion continued to show buoyed up his own sinking spirits to a considerable extent. They had now left the river far behind, and had entered upon a new phase of their journey. Several times at stated intervals they had heard that singular deep throated rumble, and felt the ground tremble under their feet. Whatever it could be that caused this strange sound, they were evidently approaching the scene of its mysterious operations, and might come upon it at any time. It was about the middle of the afternoon when Mayhew uttered the low hiss which they had settled on as a warning of danger. At that instant Roger and Dick also caught glimpses of flitting figures amidst the forest trees, which they knew must be Indians. CHAPTER XII UNEXPECTED HELP THE three dropped to the ground, where they flattened themselves out so as to be as inconspicuous as possible. Of course the prospect of approaching trouble caused the hearts of the boys to beat doubly fast, but they managed to control themselves. "Do you think they saw us?" whispered Roger, finding his head close to that of his comrade. "We will soon know," replied the other, in the same cautious manner. "They have not given a single yelp as yet. But Mayhew is beckoning to us. He wants us to crawl along after him, where these bushes will shield us." They kept as close to the ground as possible while making progress. Now and then one of them would carefully raise his head to take an observation. When this chanced to be Dick, his cousin invariably whispered an inquiry in his ear, which the other answered with a movement of the head. They could hardly believe that the keen-eyed Indians had failed to notice their presence, though it did seem strange that they should have refrained from announcing their delight at the discovery in fierce yelps, as was their custom.