Harry Urquhart sprang to his feet and listened. He heard a laugh—a wild, fiendish laugh—far away in the night. Stooping, he picked up a bare knife that was lying on the ground.
"I wrenched this from his hand," said he, showing the knife to Fernando.
The half-caste examined it in the firelight. It was a knife of Arab design.
"That," said he, "is the knife of the Black Dog."
"Why did he not fire?" asked Harry.
"Evidently because he did not wish to warn the Germans. That is a bad sign; it means that the German troops are in the neighbourhood."
The following night, when they scanned the valley, they could see no sign of the camp-fire of von Hardenberg and the Arab. The sheikh, having failed in his enterprise on the previous evening, was evidently determined to exercise greater caution. Harry examined the valley with his glasses, not only to the north but also to the west and to the east. However, he could see no sign of their enemies.
"I do not like the look of it," said Fernando. "So long as we knew where the Black Dog was, we had the whip hand of him. We must be prepared for the worst."
"Surely," said Harry, "he will push on towards Maziriland?"
"The shortest way is not always the quickest," answered the other. "As likely as not he has gone back upon his tracks, and even now is encamped somewhere behind us."