In short, Mr. Tawwab’s conversation with Danbazzar had created an unpleasant feeling of tension. “I’ll take the next watch, Dad,” said Barry; “you might as well turn in. If nothing happens, we shall have a busy day before us to-morrow.” John Cumberland hesitated for a moment, and then stood up. “You are right,” he agreed; “I will. Good-night!” “Good-night, Dad.” For a few minutes afterward he could hear his father talking to Professor Blackwell at the top end of the _wâdi_. Then came silence again. He lighted a cigarette and helped himself to a nightcap, reflecting that he might as well have two or three hours’ sleep, although the novelty and excitement of the situation were by no means conducive to easy slumber. Presently, however, he got up and walked in the direction of his own tent. Outlined against the sky beyond he could see the gaunt figure of Professor Blackwell, rifle on shoulder; and: “Is all well, Professor?” he called. “All’s well!” cried the Professor, his voice echoing eerily from wall to wall of the _wâdi_. Barry turned in fully dressed, and lay on his bed for some time listening, although he did not know for what he listened. Somewhere in the distance a jackal howled--a second--a third--a fourth--a fifth: a regiment of jackals. Then silence fell. Once he heard a distant voice. Finally he fell asleep.… He dreamed he was standing in the tomb of Zalithea. He was alone, and had reached the place by no visible entrance. On his right, against the wall was a wonderful gold sarcophagus. He found himself in a dreadful, pent-up condition. He was utterly panic-stricken. His heart was beating like a hammer. For the lid of this sarcophagus, which was hinged, was slowly, slowly, very slowly opening! Then he saw a hand appear, and in the semi-darkness of the painted tomb chamber a light shone out from the interior of the sarcophagus. It grew brighter and brighter. The hand grasping the lid was a gaunt, long-fingered hand. He did not know what to expect. He was in that curious state in which one realizes that one is dreaming, yet is horrified by the incidents of the dream. The lid had opened nearly wide enough to reveal the occupant, when Barry shook off the horror of the nightmare which had him in its clutch and sat suddenly upright. A sharp sound had awakened him. He was bathed in cold perspiration. And, as he leaped from his bed to the sandy floor, this sound was still echoing in the hills around. He knew, in the very moment of awakening, what it had been. The crack of a rifle! And now, here was an explanation of his half-waking dream. Professor Blackwell was holding the tent flap aside. Outlined against reflected moonlight he bent, looking in. Barry heard dim voices. “What is it?” he demanded hoarsely. “Ssh!” the Professor warned. “The Arabs!” CHAPTER XVI. THE HOLE IN THE WALL