"Then, what will he do when he draws near to the caves?"
"He will rob by night," said Cortes. "Under cover of darkness he will endeavour to secure the treasure."
"My brother," said the elder man, laying a hand upon the other's shoulder, "tell me, how far away is Black Dog?"
The man judged the distance with his eye.
"Sixteen hundred yards," said he.
"Nearly a mile," said the other. "I will try my luck. I have sworn an oath by the saints."
So saying, he lay down upon his face and loaded his rifle. Lifting the back-sight, he took long and careful aim, and then pressed the trigger. There came a sharp report, and the bullet sped across the valley.
In the space of a few seconds the sheikh and his followers had vanished. To hit a moving figure at that distance was a well-nigh impossible task, but that the bullet had not been far from its mark was apparent from the way in which the party had so suddenly disappeared.
Von Hardenberg was moving up one side of the valley, Harry and his companions on the other. It was therefore a race for the treasure. If Harry reached the caves first, he would be unable to enter the vault, by reason of the fact that the Sunstone was not in his possession. He would have to lie in wait for the Black Dog and the German.
For two days they saw nothing more of their rivals. There was water in plenty in the district, and presently springs and streams became even more numerous, and they entered into a country that was thickly wooded. At the same time the mountains became more wild and rugged, and it was soon impossible to make progress by way of the hills.