When he reached the wheels, he let out a great shout that filled the vastness of the cave.
"Die!" he cried. "Die the death you merit!"
At that he set the wheels in motion, and immediately the great granite rock revolved again. And Captain Carl von Hardenberg was buried alive in the midst of the treasure that was his.
The sheikh passed rapidly down the centre aisle. Half-way to the entrance he stopped, looked back, and shook his fist at the rock.
"Lie there," he cried, "and rot! In my own good time I will return."
Before the last word was from the man's lips, Fernando had lifted his rifle and fired. The bullet flattened itself against a pillar not three inches from the Arab's head. The Black Dog glanced up at the gallery and then dashed out of the entrance, so swift and agile in his movements that it would have been sheer folly to fire again.
"You hit him?" cried Harry.
"No," cried the man, with a sullen oath. "I missed. It was too dark to see."
"Too dark to see!" repeated Harry. "But he is gone! Make haste, or he'll escape!"