“What was the matter?” gasped Frank, somewhat dazed, as he crawled away and sat up. “Why did you shove me over?”

“Don’t you see?” asked Andy quickly. “He was going to hit you! Then he’d have tackled me I guess. Look out! He’s at it again!”

With a snarl of rage the man had again raised the club. But Frank was too quick for him. Fairly leaping at him, the sturdy lad tore the piece of driftwood away and tossed it some distance off.

“So! That’s how you keep your promise, is it?” the elder lad asked. “We won’t give you any more chances. We’ll tie him up again, Andy, and let him go hungry for a while.”

The man glared hatred at them, and tried to fight them with the hand they had freed so that he might eat. But the two lads were more than a match for him in his condition, and soon had him made fast again. He had eaten only a part of his dinner when he thought he saw this chance to make his escape.

“Are you going to leave me like this?” he growled, when Andy and Frank resumed their interrupted meal. “I’ll get sunstruck.”

“It would almost serve you right,” murmured Frank, “but we’ll return good for evil. Let’s make a sort of shelter, Andy.”

With pieces of driftwood they raised a framework over their prisoner as he sat on the sands. On the boards they put sea weed, of which there was an abundance, and soon the man was sheltered from the hot sun.

“We’ll have to make something like that for ourselves to-night,” observed Frank.

“Yes, and it isn’t going to be very pleasant staying here with that man, even if he is tied up,” went on his brother. “I’m afraid he’ll get loose in the night and attack us.”

“We’ll have to look well to the knots, and keep a sort of watch I suppose,” remarked Frank. “But let’s go back and finish searching in that wreck. I wonder what it is that’s in it, and where it is?”

But the boys found no answer to their questions, though they made diligent search.

“I don’t believe it’s here,” said Andy at length. “Whatever there was Paul must have taken away before he lost his memory, and he may have hidden it somewhere else. But I have another plan, Frank.”

“No jokes, I hope.”

“No, this is serious. The more I think of staying here with that man all night, the less I like it.”

“I don’t like it either, but what can we do? Dad may think we’re staying away too long, and he may come for us. He knows we started for Cliff Island. Then again he may not come for several days, as he knows we’ve got lots of food. And our distress signal doesn’t seem to attract any attention.”

“No, and that’s why I think we oughtn’t to stay here any longer. It is very seldom that vessels come here, and we haven’t much chance of being taken off. We ought to get away and in the path of the fishing schooners. Then we would be picked up.”

“Yes, but how are we going to get off? W............