On and on rowed the two students. It was a clear, balmy day, and they hated to return to the school until it was absolutely necessary.

"Let us row around Smith Island," suggested our hero, mentioning a small place in the middle of the stream, so named after a farmer who owned it. It was a rocky and somewhat barren spot, and seldom visited by anybody but fishermen.

"All right, but we want to beware of the rocks," cautioned the big youth.

The rowboat was headed up the stream, and soon they came in sight of the island. On one side were a number of bushes, overhanging the river.

"h.e.l.lo! look there!" cried Dave, a few minutes later, and pointed to the bushes.

"What do you see?"

"A motor-boat. I think it is Nat Poole's."

"Is that so? What brought him here?" questioned Gus, with interest.

"I am sure I don't know. But it's his boat, I am sure of that," went on Dave, after another look at the craft.

"See anything of Nat?"

"No, the boat is empty."

"Let us row in a little closer and see what he is doing," suggested Gus.

"He'll say we were spying on him."

"Humph! Haven't we as much right as he has to visit the island?"

"Of course."

"Then what is the use of keeping away? He may be waiting to play some trick, or something like that."

"Oh, I think not, Gus. Probably he just visited the island out of curiosity. But I'll go in if you say so."

Slowly, so as to avoid the many rocks in that vicinity, the two students brought the rowboat close up to the motor-craft. They looked into the bushes and along the rocks beyond, but saw nothing of Nat.

"Shall we call to him?" asked Gus.

"What for? I don't want to see him."

"Neither do I. His boat is tied good and fast. He must expect to stay on the island quite a while."

The two boys rowed on, past the motor-boat. Then, as they turned a point of rocks, Dave gave a start.

"Well, of all things!"

"What is it, Dave?"

"Look yonder--in between those bushes!"

"Why, it's a rowboat."

"Exactly, Gus, and do you see how it is painted, drab with blue stripes?"

"Of course--a pretty ugly boat, I think."

"Gus, that is the very rowboat used by that wild man--the one he was in when he got away from us that day!"

"Do you really mean it?" gasped the big boy, staring hard at the craft.

"I certainly do--I'd know that boat in a hundred. I never saw another just like it."

"If that's the case, maybe the wild man is on the island!"

"Just what I was thinking," answered Dave. "And I was thinking, too, that----" He stopped short.

"What?"

"Don't you remember how Nat was so anxious to know all about the wild man? And how upset he seemed to be when he heard that the fellow called himself the King of Sumatra?"

"Yes, I remember that. Do you think he came here to find the man?"

demanded Gus, quickly.

"It looks so to me."

"My gracious, Dave, I think you are right! Say, there is something mysterious about all this!" cried Gus.

"Exactly."

"Let us go ash.o.r.e by all means and see what Nat is up to," urged the big youth.

Dave was more than willing, now that he had discovered the rowboat used by the wild man. Perhaps this island was the home of that mysterious individual. If so, what was the money-lender's son doing there? Had he business with the strange creature?

"Maybe we'd better not make any noise," suggested Gus, as the boat was turned in to a convenient landing-place. To this Dave did not reply, but they landed as silently as possible. Then the rowboat was hauled up out of sight between the bushes.

From the craft used by the wild man a rude path ran up from the sh.o.r.e to the rocks beyond. A short distance from the sh.o.r.e the boys saw the marks of a wet foot, coming from the direction where lay the motor-boat.

"That was made by Nat--he got his left foot wet," said Gus.

"I think so myself," answered our hero.

They followed the marks left by the wet foot over the rocks. They headed for the upper end of the island, where there was a small grove of straggly cedar trees. Here the marks faded away completely.

"Well, we know he came this way, anyhow," remarked Gus. "He can't be very far off, for the island isn't very big."

"I see a rude log cabin!" exclaimed Dave, and pointed through the cedars. "Maybe that is where the wild man lives."

"If it is, we want to go slow, Dave. He may attack us."

"But what of Nat, if he is there?"