The boys turned away, walked perhaps a dozen paces, and then Phil heard by his side a soft whistle, low, melodious, a bar of some quaint old song. It might have been mistaken in a summer night for the song of a bird. The boys stopped, but moved on again in a moment, thinking perhaps it was only fancy. Another ten feet, and that melodious whistle came again, lower than ever, but continuing the quaint old song. The third boy from the rear stopped and listened a little longer than the others. But the sound had been so faint, so clever an approach to the sighing of the wind among the pines, that the other boys seemed to take no notice of it. Arenberg was moving along in a parallel line with them, keeping behind the pines. Phil followed close behind him, and once more he put his hand on his arm. Now he felt, with increasing force, that the man was shaken by some tremendous internal excitement. [Illustration: "The third boy from the rear stopped and listened"] The file of Indian boys moved on, save the one who had been third from the last. He was carrying a pail of water, and he lingered, looking cautiously in the direction whence the low whistle had come. He was a small, strong figure, in Indian dress, a fur cap on his head. He seemed to be struggling with some memory, some flash out of the past. Then Arenberg, rising above the breast-work of pines, his head showing clearly over the topmost fringe, whistled a third bar of the old German folk song, so low, so faint that to Phil himself it was scarcely more than the sighing of the wind. The boy straightened up and the pail of water dropped from his hands upon the soft snow. Then he pursed his lips and whistled softly, continuing the lines of the melody. An extraordinary thrill, almost like the chill of the supernatural, ran down Phil’s back, but it was nothing to the emotion that shook the German. With a sudden cry: "It iss he!" Arenberg leaped entirely over the pine bushes, ran across the frozen creek, and snatched up the boy in his arms. It was Phil then who retained his coolness, luckily for them both. He seized the fallen rifle and called: "Come! Come, Hans, come with the boy, we must ride for our lives now!" Arenberg came suddenly back to the real world and the presence of great danger, just when he had found his son. He lifted the boy in his arms, ran with him across the creek, up the slope, and through the bushes. Little Billy scarcely stirred, but remained with his arms clasped around his father’s neck. Already hostile sounds were coming from the Indian camp. The Indian boys, at the sound of Arenberg’s footsteps, had turned back, and had seen what had happened. "We must reach the horses," cried Phil, retaining his full presence of mind. "If we can do that before they wing us we’ll escape. Run ahead. I’ll bring your rifle."