For most of the time the stillness was profound. The oxen had lain down within the enclosure and were either chewing their cuds or sleeping. Two or three of the horses kept their feet, but most of them were also lying down. Occasionally the stamp of a hoof sounded dully, but nothing else disturbed the watchers. In all directions on the level plain reigned the silence of the grave. The wide sweeping Platte, though not far off, coursed between its banks with no ripple or eddy that could be heard a hundred yards away. It was hard to believe that men were abroad in this silent world, hunting for a chance to slay their fellow creatures, but such was undoubtedly the fact. The ever shifting shadows as the clouds tumbled past the moon, tantalized Alden. Much would he have preferred that the sky should be darker or lighter, provided it remained the one or the other. It was not anything he heard which gave him his first thrill of fear. He caught no sound, but it suddenly occurred to him that there was a movement in the grass a few rods out. At first he could not define its nature. It was as if some reptile, possibly a rattlesnake, was stirring at that point. The disturbance was so slight that a moment later he felt sure he had been deceived. The face of the moon cleared, and a silver flood of light bathed the grassy plain. The spot which had roused his suspicion stood out almost as at midday, when the sky is partly cloudy. “Could I have been mistaken?” he asked himself, motionless and peering into the obscurity. “Shagbark warned me to be on my guard against _everything_, but I can’t make this out.” If a serpent had been disturbed and was zig-zagging through the grass, he had nothing to fear, for it would not molest him. The occasion was one in which Jethro might be able to give help. Alden called cautiously to him, but there was no answer. He stepped softly around the rear of the wagon, but before he discovered the big fellow lying on the ground, he noticed his heavy breathing. “Asleep,” muttered his master disgustedly; “I wonder that he kept awake so long.” Without returning to his former position, Alden again scrutinized the plain spread out to view. In the flickering illumination, he could not descry anything out of the usual order of things. “It must have been a mistake but I don’t understand――helloa!” A ragged cloud again swept past the moon, whose full rays descended upon the earth. Could Alden Payne believe his eyes?