The dip in which the horses and mules stood was only a short distance from the little fortification and unless the Sioux in attacking came very near their bullets were likely to pass over the heads of the animals. The four, resolved not to abandon the horses and mules under any circumstances, nevertheless felt rather easy on that score. About three o'clock in the morning some shots were fired from the cottonwoods in the south, but they flew wild and the four did not reply. "They came from a distance," said Boyd. "They're probably intended to provoke our fire and tell just where we're lying." After a while more shots were fired, now from the north, but as they were obviously intended for the same purpose the four still remained quiet. A little later Will heard a movement, a stamping of hoofs among the animals, indicating alarm, and once more he crawled out of the breastwork to soothe them. The horses and mules responded as always to his whispered words of encouragement and strokings of manes and noses, and he was about to return when his attention was attracted by a slight noise in the bushes on the farther side of the animals. Every motive of frontier caution and thoroughness inclined him to see what it was. It might be and most probably was a coyote hiding there in fear, but that did not prevent him from stooping low and entering the bushes. The growth of scrub, watered by seepage from the stream, was rather dense, and he pushed his way in gently, lest a rustling of twigs and leaves reach the Sioux, lurking among the cottonwoods. He did not hear the noise again, and he went a little farther. Then he heard a sound by his side almost as light as that of a leaf that falls, and he whirled about, but it was too late. A war club descended upon his head and he fell unconscious to the ground. CHAPTER XI THE YOUNG SLAVE Will's first sign of returning consciousness was a frightful headache, and he did not open his eyes, but, instead, moved his hand toward the pain as one is tempted to bite down on a sore tooth. It was in the top of his head, and his fingers touched a bandage. Without thinking he pulled at it, and the pain, so far from being confined to one spot, shot through his whole body. Then he lay still, with his eyes yet shut, and the agony decreased until it was confined to a dull throbbing in the original spot.