Tall Bear's pony was standing where he had left him, and vaulting lightly upon his back, he sent him on a gallop to the top of the hill, to learn something about the new-comers. The main party of warriors were some distance off, awaiting the signal to know whether they were to fight or to join the parties whose identity was still in doubt. The couple whom Tall Bear had despatched to reconnoitre were still absent, so that he found himself alone on the elevation. It is at such times that the American Indian displays a wonderful keenness of sight and hearing. The chief sat motionless, peering into the gloom and listening. None could know better than he that he had taken a most dangerous position. If the horsemen, who could not be far off, were hostile, they would surround the hill whereon they last saw the Sioux, and unless Tall Bear kept his wits about him he was likely to be shut in on every hand. But it would have been hard for the most skilful Indian scout to take him unawares. He was certain to see and hear the approach of any one as soon as the latter could see or hear him, and the chieftain was not the one to fall asleep under such circumstances. Darting his penetrating glances here, there, and everywhere, he suddenly fixed them upon a point directly ahead. Something was vaguely assuming form in the gloom, and a minute later he observed a man walking toward him. Tall Bear leaned forward over the neck of his pony, that he might not lose the advantage of an inch of space. The stranger was advancing without any more noise than if he was a shadow, and he was alone, or, if he had any companions, they were so far behind when he was in full view as to be invisible. The man on foot came to a halt while still too far off to be more than faintly visible, and emitted a low tremulous whistle. Tall Bear promptly answered in the same manner, and then the other ran forward to his side. He was one of the two scouts the chief had sent out, and he brought important tidings. The party of horsemen which caused the Sioux such concern were white men--every one--under the leadership of the famous frontier scout Nat Trumbull. The warrior had ventured near enough to the company to recognize his voice when he gave the order for his men to move around to the south and approach the house from that direction.