In a short time Barney and the professor were returning to the camp, while, with Frank Merriwell at his heels, Old Rocks again took up the trail. Frank marveled at the swiftness with which Old Rocks swung over the ground. Through the timber they made their way, and then through a narrow ravine, and four or five miles had been covered before the guide paused to speak. "They're makin' straight fer ther lake," he said. "I don't like that." "Why not?" "Ef ther p'izen varmints has canoes--wa-al, we won't be liable ter foller 'em farther than ther lake." "That is true. We will hope they have no canoes." Onward they went once more, Old Rocks having lighted a fresh torch, which left but one remaining. The night was on the wane. Already the sounds of the middle night were hushed. The owls had stopped their hooting, and now, on noiseless wing, were making their last hunting rounds before day should come. Afar on the side of a mountain a wolf was howling like a dog baying to the moon. The stars which filled the sky seemed to prophesy of dawn. Bending low, now and then swinging his torch to fan it into a stronger flame, Old Rocks almost raced along the trail, while the boy at his heels kept close. They were like two tongueless hounds upon a hot scent. And thus they came, at last, to the lake. Not a word did Old Rocks say for several minutes, but he moved up and down the shore, reading the "sign," while his companion waited with the greatest anxiety. At length, with a grated exclamation of rage and dismay, the man flung himself on the ground. "It's jest as I feared," he growled. "Ther onery varmints hed canoes hid hyar, an' we kin trail 'em no farther." "Then what can we do?" fluttered the discomfited boy. "Northin' but wait fer daylight." Now on the still air very faintly was heard a distant tone of music; a sweet whistle, at first low, rising and falling, and then gradually becoming more distinct. It came nearer and nearer till it seemed to fill the air all about, and then, looking upward, they saw dark forms flitting between them and the stars. The wild ducks were flying. The musical note passed on, receded, grew fainter and fainter, till, at last, it died out in the distance. From the lake came a far-off trumpet call, and then another--the mellow note of the wild geese. The world was awakening; the day was near. The stars were growing paler now. In the eastern sky was a bit of gray, which slowly broadened, pushing upward and blotting out the stars. Where all before was dark, the morning twilight began to show the black forms of things. The outlines of tree trunks could be seen, and they seemed to stand like ghosts, reaching out shadowy arms, as if feeling their way through the dimness. The birds which through the long night had slept in the low bushes were beginning to chirp and flutter. All at once, Old Rocks started and clutched Frank's arm. "Listen!" he whispered.