“Mebbe that plan will work, and then again mebbe it won’t,” said the latter, shaking his head knowingly. “Mr. Evans is pretty smart, but there is them in the world that are just as smart as he is.”

Having put saddles and bridles on three of the best horses they could find in the corral, Mr. Evans and his companion mounted and rode toward the grove, Uncle Bob leading the animal that was intended for Arthur’s use.

The latter was on the lookout for them, for his father had told him that Mr. Evans advised immediate flight. He was trembling all over, and his terror made him so weak that he could hardly mount his horse; but, with his father’s assistance, he managed to get into the saddle at last, and then Mr. Evans led the way across the valley toward the road that ran to the top of the cliffs.

“Mebbe that plan will work, and mebbe it won’t. The fellows who sent poor Bob down to the inside of the earth ain’t going to get off as easy as they think they are. Mr. Evans is gone now, and I’ll tell my story to Mr. Jacobs the very first thing I do.”

The speaker was old Ike, the cook, who, from his place of concealment behind one of the outbuildings, saw all that went on in the grove. He knew that Mr. Evans intended to lead Arthur and his father to a place of safety, and he was determined to prevent it if he could.

With this object in view, he turned about and ran toward the corral at the top of his speed.

CHAPTER XXIX.
THE MYSTERY SOLVED.

“What is it George?” asked Bob Howard, turning his eyes in every direction except the right one. “I don’t see anything strange.”

Still George made no reply. He simply raised his hand and pointed with his finger toward the middle of the valley. Bob looked, and then his own eyes began to open, and his pale face grew still paler.

It did not seem to him that his nerves could possibly stand another test just then, all unstrung as they were by the terrors of that long voyage in the dark; but now he was about to witness an exhibition of the wonderful powers of nature that would have made the heart of the bravest and strongest man beat rapidly with excitement and apprehension.