Leaving Chris still peacefully snoring, the three stole softly outside the cabin. Once outside they paused and listened again for a repetition of the strange signal.

They had not long to wait for in a few minutes, it came again, a long melodious mellow note, three times sounded.

"It comes from the Gulf," Captain Westfield declared. "Let's go down to the point. We can see both bay and gulf from there."

The island terminated in a long sand point that ran out into a passage that connected the bay with the Gulf of Mexico. To it, the three hastened their steps. Just as they stepped out on the sand spit, the mysterious signal sounded again.

"There it is," Charley cried, pointing out to sea. "It's a ship."

Out in the Gulf, about three hundred yards from where they stood, a dim shadowy mass loomed up vaguely in the darkness.

"It's a ship all right," Captain Westfield agreed, "but thar's something queer about her. No ship ever comes in close to these shores. With all the reefs thar are around hyar it's too dangerous unless one knows the channels mighty well. Then, that ain't no distress signal she's sounding,—four long blasts is the distress signal the world over. Then too she ain't got lights—that ain't proper and shipshape."

Even as he spoke, a bright flash blazed up from the strange vessel's deck. It only lasted a few seconds, but in that brief space it lit up the mysterious stranger, showing a huddled mass of men in her waist and throwing into sharp distinctness every rope and spar.

"A flare," cried Walter, "they are certainly signaling some one."

"There is something familiar about those spars," Charley exclaimed. "Did you notice them, Captain?"

"No. I was looking at the hull. She sits low as a pirate craft. She's schooner rigged and about one hundred tons burden. Hallo! Here comes some one who has heard her signals. We can find out about her all right."

From the bay came the quick chug chug of a motor turning up at full speed. As she swept into the passage, the little party could tell even in the dim light that she was a large launch and traveling at a rapid rate.

"Ahoy!" hailed Charley, as the strange launch came abreast.

The launch's engine was stopped at his call, but no answer came to his hail.

"Ahoy!" he shouted again. "Can you tell us what ship that is and what she wants?"

A string of low-muttered curses came from the launch, and almost at the same minute a single fiery rocket hissed aloft from her deck. Immediately her engine began to throb again.

"Why, she's turned around and going back!" exclaimed Captain Westfield in amazement.

"Look at the schooner!" cried Walter.

From the mysterious ship came muffled orders and the creak of blocks as sails were hoisted and sheeted home.

Slowly the put-put of the launch's engine died away in the distance from which it had come, and the mysterious schooner, under full sail, glided silently away in the darkness.

"I'll be joggered!" exclaimed Captain Westfield. "That's queer. I wonder what they were up to."

"Something that will not bear the light of day, I guess," said Charley, thoughtfully. "I believe it was our hail that frightened the fellows in the launch and their rocket was a signal to the schooner to clear out. Well, I guess the excitement is over for the night and we might as well go back to bed."

Walter and the captain lay awake for some time discussing the strange incident but Charley lay long awake on his couch, silent and thoughtful. He was puzzling to determine where he had seen the strange schooner before. In the second, the flare had revealed her in the darkness, he had sensed something vaguely familiar in the low graceful hull and the set of the raking masts.

"Where have I ever seen a foremast that raked aft like that one," he pondered. Suddenly it flashed vivid and distinct in his groping memory. "No, no," he muttered to himself. "It simply can't be her. It must only be a chance resemblance. That flare only lasted a second. Guess I am getting to imagine things. I'd better forget it and try to go to sleep."

Never-the-less it was long before he rid his alert brain of the tormenting thought and compelled sleep to come.

When he awoke, it was to find his chums up before him. Chris had breakfast cooking and Captain Westfield had just returned from taking a morning plunge in the surf. Walter was not in sight, but he soon appeared bearing a sack full of turtle eggs which he had found on the beach.

"I've been exploring our island," he announced. "Say, some of the fishermen must come over here to hold their celebrations. There are several well-worn paths on the island. I followed two of them and they both led into the same place, a little clearing in a thick bunch of palms. It looks as though there had been several fights there for the ground is all trampled up as though it had been dug, and I found a couple of long, queer-looking clubs and this full bottle. What's in it, Charley? I can't make out the label."

Charley took the big black bottle and examined the label that had puzzled his chum. "It's in Spanish," he announced, then translated rapidly: "Aguardiente, 100 Proof, Manufactured by Sicava & Sons, Santiago, Cuba." He pulled the cork and a pungent reeking odor filled the air.

"Why, it's rum," said Captain Westfield.

"A kind of rum," Charley agreed, "only far stronger and more fiery. No wonder the fishermen fight if this is the kind of stuff they drink. It would make a rabbit spit at an elephant."

"Throw it away," Walter said. "We don't want the vile stuff."

"No, I think I will keep it," said his chum, thoughtfully. "I have a notion that this little bottle is going to be mighty useful some time."

"How's that?" Walter questioned, but the spell of silent thoughtfulness was still upon Charley and he paid no heed to the question.

"I wish you fellows would go down and pull the nets into the skiffs," he said, as soon as breakfast was over. "I will be down as soon as I take a dip in the surf."

"Why, what do you want the nets on so early for?" Walter protested. "We don't fish except at night, do we?"

"We need to have a little drill," Charley explained. "It will be easier for you to learn how to handle the nets in the day time, and we will not have to waste any of our precious night time practicing."

As soon as the three were gone, Charley left the camp himself. He did not pause at the beach to take a swim, however. Instead he turned into one of the well-beaten paths Walter had spoken of. He was following up a vague suspicion that had been growing in his mind and, for good reasons, he wanted to follow it out alone. If he was right in his surmises then would be the time to tell his chums. There was no use of worrying them until he was certain.

His keen eyes noted one peculiar thing that his chum had not observed the significance of. All the paths led inward from the gulf beach and none from the bay.

A few minutes' walk brought him to the cleared place Walter had described. It was only a few feet in extent and was densely surrounded by a thick growth of cocoanut palms. No one a few feet distant would have suspected its existence so well was it hidden from sight.

At the entrance to the little space, Charley picked up two heavy pieces of timber about six feet in length. "These are Walter's clubs," he grinned. "Well, I suppose one could take them for that but clubs don't generally have a nice smooth rounded hand grip at each end and clubs the length of these things would be awkward to handle at close quarters. I have an idea these were used to carry heavy burdens. They would come pretty handy for that. Just lay the thing to be carried across them and one man take hold of the ends in front and another man at the back. Strange, Walter did not notice an odd thing about this clearing too. There is not a root or twig on the ground. Men would hardly fix up a place as clean just to fight in. He is right about one thing, though, this ground does look as though it had been all dug up, and unless all my guess is wrong, it has been dug up. Let's see how near I've hit to the mark with my suspicions."

He got down on his knees and began to dig in the soft earth. In a few minutes he came upon that which he sought. It was not unexpected for all his theories had pointed the one way. As he dug over here and there, however, he grew amazed at the magnitude of his discovery. At last he ceased his digging and carefully filled up the many holes he had made trying to smooth over the face of the ground the same as it was before. This accomplished to his satisfaction, he stood up with a thoughtful frown on his face.

Should he tell his companions of his discovery, he pondered. It was of no use to any of them at present. Would it be wise to tell them yet? Some one might let slip a word in an unguarded moment that would spoil everything. "The more that knows a secret the greater the chance of its leaking out," he reflected. "No," he would not tell them at present.

Having reached this decision, he made his way back to the beach. Stripping, he took a hurried plunge in the surf and hastily dressing hurried across the island to the skiffs.

"We have got the nets all aboard," Walter greeted him with.

One glance at the heaped up nets in the skiffs' stern and Charley's face fell.

"Whew!" he whistled, "you have sure done it now. Well, it's all my fault. I should have explained to you how to boat a net. They don't want to be piled up in a heap like that. You can't run out a net in that shape. It would all tangle up and go out in lumps and bunches. When you boat a net, you want to pile the lead line up carefully on one side of the stern and the cork line on the other letting the loose webbing fall in between, then it will run out smoothly without tangles and snarls."

The nets had to be all tumbled out of the skiffs and hauled in again as Charley had directed.

His chums were quite crestfallen over their mistake, but he only laughed. "Everything is new to you and you are bound to make a lot of mistakes at first," he assured them, "but you will soon catch on. Don't get discouraged over a little mistake like that, you'll make many bigger ones before you get used to the business. Hallo, I guess we are going to have some visitors. That launch out there is heading in here."