At Frank’s words Mr. Pauling and Mr. Henderson leaped to their feet and Tom almost dropped the coil in his surprise. “By glory!” exclaimed Rawlins, who had just appeared.

“Are you sure?” demanded Mr. Pauling. “Of course I’m sure,” replied Frank. “I heard them just as plain as in New York.”

Scrambling down the ladder all gathered about the instruments, but despite every effort no sounds came to their ears.

“Well, it did before,” insisted Frank. “I hadn’t been hearing anything and then, suddenly, I heard the voices.”

Tom sprang up and rushed towards the ladder. “Keep listening,” he yelled. “I’ll bet I know how ’twas.”

Hurrying up the ladder, he gained the deck and seizing the resonance coil moved it slowly about as if pointing with a stick. Then, just as it pointed to the southeast he heard Rawlins’ voice.

“They’ve got it again,” he shouted up the ladder. “Come down and hear it.”

“If I do you’ll lose it,” Tom shouted back. “It’s this resonance coil. You only get the voices when it points to the southeast. Tell them to listen and you yell up when they lose it and get it.”

Again Tom swung the coil about and before it had moved two feet Rawlins called up that the sounds had faded away. Once more Tom swung the coil back to its former position and once again Rawlins notified him that the voices could be heard.

But Tom was wild to be down below and hastily hanging the coil to the rail by knotting his handkerchief he hurried down.

“I knew that was it,” he declared excitedly. “The coil works and they’re southeast of here. Do you know what they’re saying?”

“No, it’s Russian or German,” replied Mr. Henderson. “Wish Ivan were here.”

“What’s the matter with Smernoff?” suggested Rawlins.

“Of course!” exclaimed Mr. Henderson. “By Jove, what fools we are! Get him, Rawlins.”

Rawlins dashed from the room and returned a few seconds later dragging the big Russian with him.

“Here, Smernoff!” ordered Mr. Henderson. “Tell us what they’re saying. And no lying, either!”

Clapping the receivers over the Russian’s ears Mr. Henderson shoved him into the chair. For a moment the slow-witted fellow seemed dazed and uncomprehending and then, as the words came to him and he realized what was wanted, a strange look of mingled cunning and ferocity crossed his features and his chest heaved with the intensity of his efforts to catch every syllable.

Impatiently the others waited. To ask him to translate as the conversation went on they knew would merely result in failure; his English was too limited and his brain too slow for that.

“Might let him talk back,” suggested Rawlins in a whisper. “He could put up a yarn about escaping and find out where they are.”

Mr. Pauling shook his head. “You don’t know the men you’re dealing with,” he said. “They probably know all about his escape and his acts in New York and a word from him would simply forewarn them. I had the sending set cut off the moment I came in—I’m not risking any chance of being heard.”

A moment later, Smernoff slowly swung his big body around and with a savage glint in his eyes took the receivers from his ears and rose.

“They been done,” he announced. “No more talk. Me, I hear heem say he been try keel me, me, Alexis Smernoff. Ha! Heem teenk he get me, eh? Me, I make keel heem mos’ likely. Heem say me, I what you say—geef double cross—Ah! heem Bolsheviki keel mine boy, mine girl, mine wife. Ah! me, I help the gentlemen.”

“Yes, yes, we know all that, Smernoff!” cried Mr. Henderson impatiently, “but what else did they say? Where are they?”

The Russian spread his palms and shrugged his shoulders expressively.

“Heem no say notting more,” he declared. “Me, I no know where heem be. Heem make to talk from boat, heem talk from how you call it—boat same like thees fellow.”

“From a submarine?” cried Mr. Pauling.

“Sure, that eet,” replied Smernoff. “Sutmavine you call heem? Ah, he same like thees only more beeg.”

“Then they have got another sub!” exclaimed Rawlins. “I knew it! Darn it all, why didn’t we get him here first thing? We might have got wise to where they are.”

“Possibly,” agreed Mr. Pauling, “but I doubt it. They would not be likely to give away any secrets.”

“Now see here, Smernoff!” cried Mr. Henderson sharply. “You want to be free—you want to go to Russia. Well, you tell us where we’ll find this crowd and I’ll get you a pardon, see? Now out with it! Where does the crowd hang out—where do they stay? Not the chief—I don’t believe you know that—but where do they keep that submarine and where did you live?”

Smernoff listened, a perplexed frown on his low forehead.

“Me, I no know,” he replied. “Leetle islan’; Me, I no know hees name. He near one beeg place, one place me, I hear heem say call what you call heem Sam Dora—San Dom—me, I forget heem.”

“Santo Domingo!” shouted Rawlins. “Was that it, Smernoff?”

The Russian’s eyes lit up. “Sure!” he replied “That eet. Me I hear those fellow say beeg islan’ San Dom—San Dom’go.”

“I’ll say that’s a tip!” cried Rawlins, his face fairly beaming. “Hitches right onto the schooner left at the Caicos too. They’re almost due north of Santo Domingo and I’ll bet it’s one of those cays. Come on, let’s beat it.”

Ten minutes later the cay was a rapidly fading patch of green behind them and at her top speed the submarine tore through the smooth sea with her bow pointed for the Caicos Islands.

But before they reached their goal their hopes were dashed, for through the air from an invisible destroyer lurking below the horizon came a long cypher message from Disbrow which, when decoded, informed those upon the submarine that the deserted schooner had disappeared—vanished as mysteriously and completely as had her crew, and that a careful search of the islands had failed to reveal a sign of her or of the missing men.

“Well, that’s that,” said Rawlins, when Mr. Pauling told him of the message, “but there’s a bunch of cays and islands down there. I’ll bet Commander Disbrow didn’t hunt every one. I’m for getting down in there anyway. Maybe we can get their talk again.”

There seemed no better plan and so, giving Disbrow their position and course, they continued on their way, passing the Caicos low down on the horizon and making for the remote, uninhabited, outlying cays. In the hopes of again picking up the Russian conversation the resonance coil had been fixed on the superstructure and a man was detailed to slowly swing it back and forth through a wide arc, while below, one of the boys was constantly at the receivers with Bancroft at the regular equipment listening for messages from the destroyer or any other source.

Land was in sight ahead—low-lying, surf-beaten cays on the fringe of the Bahamas—when once more Tom heard the rough gutturals in his ears. Instantly he summoned Smernoff and with the signal bell, which had been arranged, notified the man at the resonance coil to hold it steady. Mr. Pauling, Mr. Henderson and Rawlins appeared at the same instant as the Russian and all waited breathlessly as the big fellow seated himself at the instruments. But only a few words came to him in the tongue of his native land and they were meaningless to him. Mere numbers, but which, after he had repeated them several times and his hearers were convinced he had made no mistake, caused the others to glance at one another and to retire behind closed doors the moment the Russian was out of sight. In the meantime Rawlins had hurried on deck and had asked the man at the coil for the direction in which it had pointed when the bell had sounded.

“Southeast by south one-quarter south, Sir,” he replied.

“Well, they’re not on those cays!” Rawlins announced as he joined the others. “The coil was pointing southeast by south one-quarter south and the cays are just about due south by east. What did you make of those numbers?”

“Latitude and longitude, I should say,” replied Mr. Pauling. “If so, where would they bring it?”

Rawlins left and returned a moment later with a chart. Spreading it on the table he ran his parallel ruler over it.

“If they are latitude and longitude they’re not anywhere within five hundred miles,” he declared, “and,” he continued, “I don’t believe they were latitude and longitude. One was X 3568 and the other 46 B 15. Whichever way you take it that would be way outside of the West Indies and I’ll bet my best hat to a stale doughnut that they’re some cypher numbers. By the jumping Jupiter! I have it! That’s the way the Hun planes used to signal their gunners to direct their fire! Those fellows on that sub are directing some one to somewhere. Yes, sir, and I’ll make another guess and that is they’re onto us and are breaking for headquarters as fast as they can beat it. Likely as not those numbers refer to us. I’ll say that’s it! We never heard a peep from them till we began testing that radio under water. Shouldn’t wonder if they were lying low not far off and heard us.”

“You may be right,” agreed Mr. Pauling. “But it’s all guesswork. Of course we did not hear them before as we had not set up the instruments and had not used the resonance coil. But tell me, Henderson, how is it we get them on that and don’t get them on the regular instruments?”

“Too weak for the latter,” replied the other, “you forget the boys are using three stages of amplification and those crystals. But if that detector is right we should be able to hear that other sub if she’s near. Are there any cays southeast by south one-quarter south, Rawlins?”

“Not this side of Haiti or Santo Domingo, but Smernoff said they were talking from a sub so that don’t count.”

“H-m-m,” muttered Mr. Henderson. “Rather like searching for a needle in a haystack. For all we know they may not be headed for their hiding place.”

“No, they may not,” admitted Mr. Pauling, “but I think Rawlins is right in that part of his surmise. If the submarine picked up the schooner’s crew as we assume, then they would naturally go direct to headquarters to report. If they continue to talk there is no reason why we should not trail them and eventually run them down.”

“Well I’m going to pump that Smernoff,” declared Rawlins. “I’ll bet he can tell us something. Not that I think he’s lying, but he’s just naturally thick as mud and he doesn’t get all we say to him. He must be able to tell something about the island if he lived there, and if he does I may be able to recognize it from his description.”

“Well, good luck, Rawlins,” laughed Mr. Henderson as the diver hurried aft. “Sorry you can’t talk Russian.”

But when, an hour later, Rawlins reappeared the others knew instantly by the expression on his face that he had learned something of value.

“I’ll say he knew something!” cried Rawlins gleefully. “Had the deuce of a job getting at it—couldn’t seem to make him understand, but got it little by little. He says the island was about a mile long and half a mile wide, that it was high and rocky in the middle, that one of the landmarks was a big turtle-shaped rock standing out of water just off a point and that the men lived in rooms or barracks which were cut in the solid rock.”

“That’s all very interesting—if true,” said Mr. Pauling, “but how does it help? There are probably a thousand islands of that size with similar high rocky centers and turtle-shaped, undercut rocks off their points. Why, the description might do just as well for New Providence.”

“Yes, except for one thing,” replied Rawlins, “and that of course was the last thing I got out of the old duck. Probably thought it wasn’t worth mentioning.”

“Well, out with it! What was it?” demanded Mr. Henderson.

“Rather I should have said two things,” Rawlins answered. “The first was the fact that there were rooms cut out of the rock and stairways cut from the rock leading up to an old fort or wall also cut from the solid rock. The second was that the place was inhabited by a sort of giant rat and that the men caught and ate them.”

“Might have been China!” laughed Mr. Pauling.

“Yes,” agreed Rawlins, “but it’s not. I know the place as well as I do my own island back in the Bahamas. There’s only one island in the West Indies that it could be. There aren’t many with ruins of forts cut from solid rock. I don’t know of another that has them and a turtle-shaped rock off the point, and I can swear there’s not another that has both those and the big rats as he calls them—the Jutias—and that’s a little island off Santo Domingo known as Trade Wind Cay.”

“Jove!” exclaimed Mr. Henderson. “Are you sure of that?”

“I’ll stake my life on it,” replied Rawlins soberly. “I’ll bet, if we head for Trade Wind Cay, we’ll find their hang-out. And here’s another bet—or hunch, or whatever you want to call it. Smernoff says it never took over a day for the sub to go to the chief’s place and return. Now there’s no blamed bit of land within half a day’s run of that cay except Santo Domingo and it’s dollars to brass tacks the old High-Muck-a-Muck hangs out there. Mighty good place too—lot of it wild and uninhabited, plenty of caves, fine hidden harbors and bush everywhere.”

“Rawlins you should be in the Service!” declared Mr. Pauling enthusiastically. “You’ve the imagination, the perseverance, the energy and the logic. I believe you’re right. I’m with you for Trade Wind Cay.”

“Well I had a sort of an idea I was in the Service, just at present,” laughed Rawlins, “and if the old sub don’t bust or run aground or shake herself to pieces we’ll be within sight of that cay inside of three days.”

No further messages were heard that day and all through the night they kept steadily on. The last bit of land had dropped from sight and far off on the southern horizon a faint misty cloud hung which Rawlins and Sam both insisted was the higher mountain tops of Haiti or Santo Domingo. Then, just before noon, the man in the conning tower called down the speaking tube to those below.

“Sail ahead!” he announced. “Looks like a schooner and about three points off our port bow.”

Ordinarily the sighting of a schooner would have caused no interest or excitement and would merely have called for submergence until out of sight, but with the knowledge that the mysterious submarine was somewhere in the surrounding waters and remembering the strange disappearance of the schooner reported by Disbrow, those on board the submarine hurried on deck to have a look.

“It’s a schooner all right,” declared Rawlins, after studying it through his glasses, “and it fits the description of the one that Disbrow lost to a ‘T.’ Shall we run over and have a look at her?”

“I suppose it would be wise,” agreed Mr. Pauling, “but how about being seen? I think we had better submerge and watch her through the periscope. If it’s another schooner we can get away without being seen—I doubt if these West Indians would notice a periscope—and if it is the schooner we want, we can either run alongside and board her or else keep watch at a safe distance and perhaps secure valuable information as to her objective.”

A few moments later only the submarine’s periscope was visible above the sea, and below, Rawlins, Mr. Pauling and the navigating officer kept their eyes glued to the eye-pieces. Now the schooner was plainly visible, even from the low elevation of the periscope, and as they drew ever nearer Rawlins noticed something peculiar about her. Although she had all lower sails spread they were drawing but little in the light wind and yet she was moving at a fairly good speed.

“I’ll be hanged!” Rawlins suddenly exclaimed. “She’s being towed!”

“Being towed?” repeated Mr. Pauling. “There’s nothing towing her.”

“Nothing!” almost shouted the diver. “Nothing! By all that’s holy she’s being towed by a submarine!”

“Yes, Sir; that’s what she is, Sir,” responded the navigator in matter-of-fact tones. “Shall we put a shot across her bows, Sir?”

Mr. Pauling burst out laughing despite the excitement and surprise of their discovery. “This is not wartime,” he replied. “We’d get into no end of trouble by such methods. That schooner is flying the British flag and for all we know to the contrary is an honest vessel in distress being towed by one of our own submarines.”

“What the deuce is up now!” interrupted Rawlins. “Look there! She’s stopped! Say, yes, darned if she isn’t. Jumping jiminy, the sub’s cut loose!”

“She’s no longer moving,” admitted Mr. Henderson. “Perhaps they’re waiting for us.”

“No, the sub’s gone!” declared Rawlins. “Don’t you think so, Quartermaster?”

The quartermaster, a grizzled but husky old sea dog, gazed silently for a minute.

“Yes, Sir,” he replied, “she seems to has, Sir. Sorry we couldn’t have bumped her, Sir.”

By now the schooner was close at hand and Rawlins was on the point of suggesting that they should run alongside and board her when Frank shouted that there was a queer noise in the receivers.

“It sounds like a hard wind or an electric fan,” he cried. “Come on and listen. What do you suppose it is?”

“The sub’s screw!” replied Rawlins. “I’ll bet she’s hustling. Shall we board that schooner?”

“Better,” replied Mr. Pauling, and orders were at once given to emerge. As the submarine, her decks awash, approached the schooner, those upon the under-sea boat’s superstructure gazed curiously at the craft they had overhauled. That she was the missing schooner they had sought all were sure, for she fitted the descriptions perfectly and the fact that she had been towed by a submarine was still further evidence. They were now within a few hundred yards and yet not a soul had appeared upon the schooner’s decks.

“Darned if she isn’t deserted again!” exclaimed Rawlins. “I’ll——”

At that instant the schooner’s masts seemed to spring into the air; a burst of flames and smoke shot from her decks, there was a terrific detonation and as the submarine rolled, pitched and rocked to the force of the explosion those upon her clutched wildly for support while all about fell bits of torn and shattered rigging, spars and canvas. Scared and white-faced those upon the submarine stared at one another, steadying themselves with their grasp of the handrails, soaked to the waist by the great waves that had washed over the half-submerged craft and speechless with the surprise and shock of the explosion. Only bits of wreckage marked the schooner. She had been blown to atoms.