“Well, what’s the first thing to be done?” asked Andy, after he had assisted Frank to pull the boat up on the beach beyond high-water mark.

“There’s plenty to do,” declared his brother. “In the first place we’ve got to decide whether we’ll stay on shore over night, or sleep on the boat. If we stay on land we’ve got to bring our grub ashore. Then, the next thing is to map out a plan so we can search the island, and not go over the same ground twice.”

“My! You’d think you had done this sort of thing all your life, and had it down to a science,” declared Andy with a laugh.

“Well, if it’s going to be done at all, it might as well be done right. This thing is getting serious, and I want to clear it up if possible. For our sakes as well as for Paul’s.”

They talked the matter over at some length, and decided that it would be more fun to camp on shore instead of going back and forth to the boat to sleep and eat.

“The weather is warm,” said Andy, “and we can sleep out in the open, especially as we have plenty of blankets. And it will be jolly to build a fire on shore and sit around it nights. Just like some old sea pirates. Wow!”

“Easy!” cautioned his brother. “This isn’t a joy-picnic. We’re here on serious business, and there may be some danger.”

“But we might as well have some sport along with it,” argued Andy, who could not help seeing the funny or bright side of everything. Frank, though more serious, did not despise a good time by any means, but he went at matters more determinedly than did his brother.

“To my notion, the first thing to do is to go at this search with a system,” went on the older lad. “We’ll climb up to the top of the cliff, and see if we can make out anything from there. If that man is here he may have set up a camp, and built a fire. If he has, we can easily see it from the cliff. Then we will know where we’re at.”

To this Andy agreed, and soon they were toiling to the top of the high land that ran lengthwise of the island, roughly dividing it into two parts. It was no easy matter to reach the summit, and several times the boys had to stop for a rest. But finally they were at the goal.

Below them, on all sides, washing the rocky shores of the island were the heaving waters of the great bay. They could take in most of the shore line, irregular and indented as it was, but, look as they did, there was no sign of life.

They saw no curling smoke from a campfire. They saw no figure of a man—the man whom they had so fruitlessly pursued. Nor was there any vestige of a big motor boat half-burned.

“Well, nothing doing so far,” remarked Frank, after a pause. “Now we’ll go down and begin a circuit of the shore and see what is in some of the caves.”

Slipping and sliding over the loose stones and gravel, they reached the bottom of the slope near where they had drawn up their boat. The sight of this craft gave Frank an idea.

“Suppose while we’re on one side of the island that man—or someone—should happen to come along?” he suggested. “He’d make off with our boat, sure.”

“Probably,” agreed Andy. “But we can prevent that.”

“How?”

“By hiding the oars. We’ll shove ’em under some bushes quite a distance back, so they can’t be found.”

Frank agreed that this was a good idea, and though there was a chance that someone might land in a motor boat and tow off their rowing craft, still they had to take that risk.

Then began a systematic search of the island. They went along the shore, and looked into many small caves. The interior of these was dark, but they had each provided a pocket portable electric flash lamp, so that they were able to illuminate the caverns.

“Nothing here,” announced Frank, after an inspection of the first one. And that was the result in all the others that they penetrated before dusk. By nightfall they had covered perhaps a quarter of the shore line and then they turned back.

A roaring blaze was kindled on the sand from the plentiful supply of driftwood that strewed the beach, and at the cheerful fire they sat and talked as they ate their supper.

“Jolly fun, isn’t it?” asked Andy.

“It sure is, even if we don’t discover anything. I wish Paul was along.”

“Perhaps it’s just as well he’s home,” commented the younger lad. “I have an idea that this man keeps informed of our movements, and I don’t fancy having him sneak up on us during the night, which he would be very likely to do if Paul was with us.”

“That’s so. But, speaking of night, what are we going to do about sleeping?”

“Under our boat, with our blankets spread out on the sands,” said the younger lad. “It’s plenty warm enough.”

It was not a half bad way to spend the ni............