And, at that moment, a violent blow descended upon his head and stretched him senseless on the ground. The Arab sheikh had come to the assistance of his employer in the nick of time. His quick eyes had taken in the situation at a glance. He had seen the Sunstone in the hands of Harry Urquhart, and, lifting his rifle by the barrel, he had brought down the butt upon the boy's head.

For him to snatch up the Sunstone was the work of an instant. And a moment afterwards the Black Dog was flying in the night, carrying in his arms the unconscious body of von Hardenberg.

[CHAPTER XXIV—The Caves]

Fernando, bringing his rifle to his shoulder, fired a shot at random in the darkness. It was the last round they had. A laugh came back from the distance.

Without a word the guide put down his rifle on the ground and examined the wounded boy.

"He is stunned," said he. "He will recover presently."

So saying he lifted Harry in his arms and carried him a distance of about a hundred yards to a place where there was a small stream in the valley.

There he bathed the boy's face and hands, washing the blood from the wound in his ear. Presently Harry recovered consciousness, sat up, and looked about him.

"Where am I?" he asked.

It took but a word to remind him of what had happened, and then he remembered that he had held the Sunstone in his grasp. He looked up at Jim and smiled.