"Are you hurt?" asked Jim.
"No," said Harry. "I am not hurt. But get me out of this; I can't move."
With quick hands they lifted the beams and rafters that pinned the boy to the ground, and, a moment after, Harry was on his feet.
The young leopards gathered together in a corner of the chamber. Then, one after the other, they sprang over the ruined wall like cats, and disappeared into the night.
"The sheikh!" cried Fernando. "Where is he?"
"I have not seen him," answered Harry.
"He came here to-day," said Cortes, "and pitched his camp. Look here, what's that?"
He pointed to the ground, where lay something that was white as snow. It was a bone.
The two boys drew back in horror. Fernando was undismayed. He calmly picked up the bone and examined it in the moonlight.
"This is the shin-bone of a camel," said he. "Moreover, of a camel that was killed to-day. As my brother says, the Black Dog was here."