"I hope this isn't another precipice," thought the boy, as the pony half-slid, half-clambered down in the darkness. Presently his hoofs splashed in water, and Rob knew they were crossing a creek. He drew back on his single rein and listened intently. Fortunately the wind, what there was of it, set toward him.

Borne on it he could hear distant shouts and cries. To his intense satisfaction, it seemed to him that they were farther off than when he had first heard them.

"Gained on them!" muttered Rob triumphantly. "Now, if daylight would only come along——"

But it was long to wait till daylight, and in the meantime Rob did not dare remain where he was. The Indians probably knew the mountains like a book, and would work them on a system. In such an event his only salvation lay in keeping moving. All at once he stopped, with a sudden heart leap, as his pony scrambled up the farther bank of the creek.

A shrill cry sounded close behind him.

Could it be possible that the advance guard of the Indians had approached him so nearly?

The next instant Rob gave a laugh of relief. The shrill cry came again.

"Whoo-to-too, who-o-o!"

"Only an owl," exclaimed the boy. "Hullo, though, that's funny! There's another answering it—and by George! there's another!"

From the woods to the right and left had come similar hoots to the owl-like sound he had noted behind him. At the same instant, the unmistakable sound of a dislodged stone bounding and rattling down the steep incline he had just descended was borne to his ears.