A half hour after his friends had fallen asleep Deerfoot put away his book and rose to his feet. It was profoundly still. On his right flowed the slightly muddy stream, no more than fifty feet wide and of shallow depth. In other directions stretched the slightly rolling prairie until lost in the gloom. The moon was near the full, but its light was treacherous and uncertain because of the masses of clouds that slowly drifted across its face. At times one could see quite clearly for a hundred yards or more, and then the shadows crept up to the camp, whose fire threw out comparatively little light. Now and then the watchful sentinel was able to detect the dim outlines of the farther shore, even when the surface of the stream did not reflect the mild glow of the fire. Nothing escaped his vigilant eye. It was not yet midnight when Bug, the horse of Mul-tal-la, showed a strange restlessness. He whinnied softly two or three times, and finally came to his feet. Deerfoot moved silently to his side, patted his neck and spoke soothingly. The animal showed no alarm, but rather curiosity. His nose was pointed to the south, where he seemed to scent something unusual. The Shawanoe waited till the moon emerged from the clouds and then peered in that direction. He could detect nothing out of the common. He walked a little way and again waited for the moon’s face to become unveiled. Still all looked the same as before. He went back to Bug and found him in the former position, with ears pricked forward, nose thrust slightly out and breathing more rapidly than was his wont. The other horses gave no sign of disturbance. The Shawanoe was puzzled. He felt that if this dumb brute was able to detect the approach of danger he ought to do the same. Kneeling, he pressed one ear against the damp ground. As he did so he was sensible of a faint rhythmic, velvet-like tremor, which was inaudible when he raised his head. Using the earth again as a medium, he listened and brought all his faculties into play. The singular pulsation neither increased nor diminished. The best comparison he could make was to that of the multitudinous tramping of thousands of tiny feet upon the earth miles away, recalling the gradual subsidence of the racket created by the stamping of the bison. Deerfoot knew it was not produced by those animals. It could not have been elk or deer, for they never herded in such vast numbers, nor could it have been made by wolves, since their tread was too soft for the sound to penetrate far. The Shawanoe was mystified. Rising to his feet again he stood gazing southward, wondering what strange thing was to come out of the flickering moonlight. But none appeared, and hearing a movement of Bug, he turned and saw him disposing himself for the night. He lay down on the grassy earth, prepared to continue the rest which had been broken so curiously. [Illustration: “‘Helloa!’”]