Louise and Ted Mackay did not go to the police headquarters that night. They were too miserable, too discouraged by the outcome of their excursion to the island. After leaving the plane at the airport, Ted called Captain Magee on the telephone, and briefly related the results of their flight.

Supper was a dreary affair for them both. It was only by putting forth a tremendous effort that they ate at all—in an attempt to stave off exhaustion. The ice cream, at least, tasted good to Louise, for she was still very hot.

The worst ordeal of all came after the meal, just as the saddened young couple were passing through the hotel lobby to take the elevator to their room. Louise suddenly recognized two familiar figures at the desk, two men who had just arrived with their luggage. Mr. Crowley and Mr. Carlton—the fathers of the two unfortunate girls!

The tears which Louise had bravely forced back ever since her collapse at the discovery of the matchbox on the island, rushed to her eyes again. How could they ever tell these two men the terrible news?

For an instant she hoped they would not see her or her husband, that she could at least put off the evil tidings until the morning. But it was not to be. Linda's father recognized her instantly, and came quickly towards her.

"Louise!" he exclaimed, holding out his hand. "And Ted! Any news?"

Louise could not answer for the sob that was choking her, and Ted, shy as he always was, knew it was his duty to explain.

"Bad news, Sir," he said. "We had information this morning that the girls were stranded on an island in the ocean, and that their autogiro had been stolen from them. As you probably read in the newspaper, it was found yesterday.... We—Lou and I—flew to the island where the girls were supposed to be, this afternoon, and found evidences of their camp—burnt out fires—but no trace of the girls."

Mr. Carlton looked grave.

"But they may have been rescued," suggested Mr. Crowley, who had the same optimistic disposition as his daughter.

"Possibly," admitted Ted. "But if they had, wouldn't we have heard? The whole country is waiting for news of those two brave girls."

"I'm afraid you're right," agreed Mr. Carlton, darkly. "Yes, you must be right. Foul play——"

"Or the ocean!" put in Louise. "Oh, the cruel, dreadful ocean! If it couldn't swallow Linda up on her flight to Paris, it had to have its revenge now!"

"Have you had your dinner, Sir?" asked Ted of Mr. Carlton.

"Yes. On the train. Suppose we get our rooms—I'll ask for a private sitting-room—and then we can all go up and discuss the matter together from every angle, and decide upon what is the best thing for us to do."

Louise brightened at this ray of hope.

"Then you're not going to give up yet, Mr. Carlton?" she inquired.

"Never, till we find them—dead or alive. We're going to think of no news as good news."

Mr. Crowley nodded his approval.

"I have a week's vacation," added Ted, "and I shall be at your service."

"Thank you, my boy," answered Mr. Carlton, gratefully. He was a great admirer of Ted Mackay, ever since he had recovered from his prejudice against him because he was the son of a ne'er-do-well.

The new-comers made their arrangements at the desk, and were fortunate enough to secure a very pleasant suite. Louise and Ted went up in the elevator with them, and Mr. Carlton ordered coffee to be sent to the room.

They settled down into the easy chairs and Louise poured the iced-coffee. The evening was hot, but there were large windows on three sides of the sitting-room, and a lovely breeze was blowing. Mr. Carlton brought out cigars and offered one to Ted.

"But I suppose you'd rather have a cigarette," he said, when Ted refused.

"No thank you, Sir. I never smoke. A great many of us pilots don't. We want to keep as fit as possible."

Mr. Carlton nodded. Linda had never expressed any desire to smoke, and he supposed it was for the same reason.

"There are two places where the girls might be," he said slowly, as he puffed on his cigar. "On another of those small islands, off the coast, or in some boat—on the ocean. If they had reached the coast, we should have heard of it."

"A boat!" repeated Louise, with sudden inspiration. "There was that broken down motor-boat, that the girl and the gangster used to get to the island! Could Dot and Linda have gone off in that?"

"What boat?" demanded Mr. Carlton and Mr. Crowley, both at once.

Louise explained by repeating most of the story which they had heard from Susie that morning.

"Funny we didn't think of that before," observed Ted. "Come to remember, I didn't see any boat this afternoon. Did you, Lou?"

"No, I didn't. And we searched the whole island," she explained to the older men. "We'd surely have seen it if there had been one."

"This sounds hopeful!" exclaimed Mr. Crowley, joyfully. "If it didn't have a leak——"

"But didn't you say that it was broken?" asked Mr. Carlton.

"The girl said the engine was broken, but as far as I know, the boat itself was sound," replied Ted.

"Linda could fix the engine!" cried Louise, almost hysterical in her relief. For the first time since the finding of the matchbox, she actually believed that Linda and Dot were still alive.

"We'll work on that theory, anyway," decided Mr. Carlton. "And go out on the ocean tomorrow."

Before they could discuss their plans any further, the telephone on the desk interrupted them, and Mr. Carlton was informed that there were two young men who wanted to see him—Ralph Clavering and James Valier.

"Well, of all things!" exclaimed Mr. Carlton, who had not even known that the boys had started South. "Yes," he added to the clerk on the phone, "ask them to come up right away, by all means."

"Who? What?" demanded Louise, eagerly. "Any news?"

"I don't know yet. Ralph and Jim are here."

"They would be," smiled Louise. Linda could never get away from Ralph Clavering, no matter how far she went.

A minute later the boys appeared, dressed in camping clothes, looking very unlike the neat, immaculate young men they always appeared to be at Spring City, or at Green Falls. Even if they took part in athletics at home, their white flannels were always spotless. But now, except for the fact that their faces were clean and shaved, they looked like tramps.

Ralph and Jim were just as much surprised to see Ted and Louise as the latter were at their visit.

"Where in the world have you been?" demanded Louise, in amazement at their appearance. "You both look as if you had been ship-wrecked and lost besides."

"We have," muttered Jim, sinking wearily into a seat, and extending his long legs in front of him. "Please pardon our slouching, Lou—but we're dead."

"But where have you been?" repeated Mr. Carlton.

"In the Okefenokee Swamp!" answered Ralph. "And if Lou weren't here, I'd tell you what it's like, in no uncertain language!"

Mr. Carlton smiled, and yet he was horror stricken. If these boys found it so dreadful, what must it have seemed like to Linda?

"Tell us about it!" he urged. "But wait, have you had your supper?"

"Yes. We had food along with us. We left the canoe at the edge of the stream, and taxied back here, because we have rooms in this hotel. They told us at the desk that 'Miss Carlton's father had arrived,' so we didn't wait even to change our clothing. We had to get the news of the girls immediately."

"I'm afraid there isn't much to tell," sighed Louise. "At least nothing hopeful." Briefly she repeated what she and Ted had been doing all afternoon, as a result of Susie's capture and story, and she displayed the matchbox, with the name of Spring City stamped on its lid.

"I recall Linda's getting that from her aunt," remarked Ralph, dolefully. "She asked for half a dozen boxes, and Miss Carlton got them right away, so she wouldn't forget."

"Now tell us what you boys have been doing," urged Mr. Crowley. "And Louise, why don't you pour them some of this iced-coffee? It really is very refreshing."

Briefly Ralph told his story, aided now and then by Jim. Their second expedition into the swamp had been as useless as their first, though they admitted the superiority of a canoe over a motor-boat, if one knew where to go. But they had become hopelessly lost in a couple of hours, in spite of their maps, and, as time passed, they became all the more certain that the girls were not in the swamp. They decided to turn back, in order to concentrate their efforts on the islands near where the autogiro had been found.

Susie's story naturally confirmed their suspicions, and they instantly agreed with Mr. Carlton to abandon all further search of the Okefenokee.

"I believe the thing to do," announced the latter, after serious contemplation, "is to hire a yacht, and cruise all along the Georgia and Florida coast. The most reasonable explanation to me is that Linda and Dot are adrift somewhere in that motor-boat. Either the engine is broken beyond repair, or the gasoline has given out."

"Or that terrible storm has wrecked them," faltered Louise, who could not silence her fear of the ocean. "Upset that little boat, and——"

"Don't, Lou!" cried Jim. "Don't even think of things like that, unless we find an empty boat!"

"I'll try not to," she promised.

"Well, whatever has happened, the ocean is the place for us to be, if we hope to rescue the girls," concluded Mr. Carlton, "You all agree on that point?"

Everyone assented, and Ralph and Jim expressed their desire to get into action immediately.

"We ought to be able to get a yacht tomorrow," continued Mr. Carlton. "Because of the publicity of this affair someone who has one ready will probably be glad to rent it to us on the spot. I think I'll go to the newspaper office tonight, and have the request broadcast by radio."

"Great!" exclaimed Louise, jumping up excitedly. "And can we all go with you tomorrow, on the cruise, I mean, Mr. Carlton?"

"You can do just as you prefer—go with me, or use your own plane to fly around over the islands."

"I think that would be the better plan for us, Sir," put in Ted. "And we can keep in touch with you by signals."

The group separated at last, the older men to call their families by long-distance, the young people to get a good night's sleep after their strenuous day. In the morning they re-assembled at breakfast, when Mr. Carlton announced the good news that he had been offered a yacht by a wealthy man in Jacksonville.

"He even refused to take any rent for it, much as I urged him to," he added. "And he's lending us the crew besides. It seems too good to be true."

"All of which goes to show just how popular Linda is—with everybody!" explained Louise. "Oh, we simply must find her!"

There were no preparations to be made for the cruise, because the owner of the yacht assured Mr. Carlton that everything was in readiness, so by ten o'clock on the morning of July third, the little party, composed of the two fathers and the two boy-friends of the lost girls stepped aboard the boat. It was a beautiful little yacht, complete in every detail. Under any other circumstances the men would have been overjoyed at the prospect of such a pleasant trip. As it was, they were too worried to think of anything but Linda and Dot.

"What a marvelous time we could be having if the girls were aboard!" lamented Ralph. "Dance and play bridge all day, every day, with no other fellows to cut in on us, and take them away! I say, Jim, we might even come back engaged if we had a chance like that!"

"Much more likely they'd be so sick of us they'd never want to see us again!" returned the other, shrewdly. "No—cruising's all right. But I'd rather be in Green Falls if Linda and Dot were with us."

"Maybe this will teach Linda a lesson," grumbled Ralph. Then he suddenly remembered her job, with the Spraying Company in Atlanta. He couldn't pretend to be sorry if she lost it.

The speedy little yacht cruised all day along the coast, while the men played bridge, and smoked, and ate the most excellent meals, cooked and served by an efficient staff. But underneath all this comfort ran an under-current of anxiety, especially towards evening, when darkness came on, and no sign of the girls had been seen.

Several airplanes had flown over their heads during the day, and once they saw Ted's plane. Dropping low, Louise waved her handkerchief, which was the pre-arranged signal to tell them that the flyers had found nothing, and Ralph waved his in return, conveying the same information. Should they have anything to report, Ted announced that he would put his plane through a series of stunts, and, in the case of the yacht's making a discovery, Jim Valier promised to climb up on the rail.

But the airplane and the yacht passed each other with only a dismal fluttering of handkerchiefs.

"Something's bound to happen tomorrow," said Jim, as he crawled into his bunk that night. "It'll be the fourth of July!"

"By Jove! It will!" exclaimed Ralph. "We ought to get some bang-up excitement!"

But the thing that happened was what they had all been silently dreading—the fate which only Louise had mentioned, that night in the hotel sitting-room.

About noon—off the coast of Florida—Jim Valier spotted an overturned old motor-boat, bouncing helplessly about on the ocean!