"I am sure of it."
"How sure?"
"Well, the chart which John made has this island on it, and a mark which shows something like it directly to the south. I saw that several days ago."
"When did he make the drawing?"
"Since he has been on this island."
Harry emitted a low whistle. "I thought John had something in his mind all along. What do you suppose he expects to find in that particular cave?"
"Well, not money; that's sure. It might be a good idea to do some thinking and searching on our own account."
"I have often wondered, since we have been on Wonder Island, and more particularly, since we landed here, whether it would not be possible to trace some of the unsolved mysteries of Wonder Island to this, or some other island."
"Yes, I have often thought of that. We have gone over every part of that island, and found no trace[p. 143] of the other boat load, that is of the boys who came ashore on the Investigator's No. 3. None of the tribes ever knew or heard of that boat, nor was there ever a trace of the members of that crew.
"That is the mystery. Some one brought the boat to the island. Some one took it inland. Some one, a man by the name of Walter, wrote a note addressed to Wright, who was one of the companions of John when he was shipwrecked, but Wright knew nothing of Walter. If the solution of this matter does not lie in some other island, we might as well give it up."