This loping trot was kept up for fully two hours, at the end of which time Tom was certain that he was approaching the river again. He still pressed forward for another hour, when he came to a halt. Although he had continued this great exertion for so long a time, yet so good was his wind that when he paused there was no perceptible quickening of the respiration. Years of training had made him capable of standing far more trying tests of his strength than this. The scout carefully turned his head from side to side, looking and listening. All was still, and his ear caught no ominous sound. Then he moistened his finger and held it over his head. Yes, there was the least possible breath of air stirring, as was told him by the fact that one side of the moistened finger was slightly chilled. Everywhere, right, left, in front or rear, so far as the bright moonlight permitted his vision to extend, was the same dead level of treeless plain. Kneeling down he applied his ear to the ground. Could it be? There _was_ a sound thus carried to his ears--the very sound which above all others he dreaded to hear. It was a faint, almost inaudible, tapping upon the earth. Far away it was, but drawing nearer every minute. The scout knew what it meant. It was the sound of horse's hoofs! CHAPTER IV. OUTWITTED. "I'll match them Apaches agin the world for shrewd deviltry," exclaimed Hardynge, unable to suppress his admiration even in the moment which told him of his own increased personal danger. "By some hook or crook, the Old Boy only knows what, they've found out my game, and are after me. Ah! if I only had my mustang, Thundergust, with me!" Tom now changed his direction more to the north, his intention being to strike the river much sooner than was his original purpose. It was the only thing he could do to escape the redskins, who showed such a wonderful skill in following him up.