When Rawlins called on Mr. Pauling the following day the first thing that greeted him was the announcement that the submarine had been found.

So excited were the boys that for some time they could not convey an intelligible idea of the matter and before Rawlins could grasp the details of the discovery they were plying him with questions as to his opinion in regard to it.

“What do you think became of the men?” cried Tom.

“Do you suppose it was their boat?” demanded Frank.

“How do you think it got so far away, if it’s theirs?” put in Tom.

“We puzzled over it for hours last night and no one can explain it,” declared Frank.

“Easy, boys, easy!” laughed Rawlins. “One thing at a time. Shorten sails a bit and let me get my bearings. You say the destroyer found a submarine floating just awash and absolutely deserted one hundred miles off the coast? I don’t believe it was that sub!”

“Could you identify it by a description—anything about it?” asked Mr. Pauling.

“Well, I don’t know,” admitted Rawlins. “I know it was a German sub and I’d recognize it if I saw it; but whether I can be sure of it by a description depends upon the description.”

“They’re towing her in,” Mr. Pauling informed him. “She was disabled and unable to come in under her own power. Until she arrives all we know is that she is a German boat—one of the medium-sized craft—that she carries torpedoes and a gun and that she is painted sea-green.”

“Fits her like an Easter bonnet,” declared Rawlins. “Under water I could not be sure of her color, but it was not black or gray—everything takes on a greenish look under water. Did they find anything suspicious on her?”

“That I can’t say,” replied Mr. Pauling. “They didn’t report whether they made any discoveries or not.”

“But if it is the submarine, where are the men?” reiterated Tom.

“Search me,” replied Rawlins. “A lot of things may have happened to them. Something may have gone wrong so they were obliged to come up and knowing they would be captured they took the sub’s boats. Or again, they may have decided to desert the sub and scatter—probably they knew the chaps we got, and suspected they’d confess. It would have been an easy matter to run in close to shore, take to the boats and land and then sink the boats in shallow water so as to leave no trace. Or some ship might have picked them up. By the way, I’ve been puzzling over something. How do you suppose that sub got in and out of the West Indies without being seen and reported. If she carried contraband in and loot out she must have gone to some port.”

“Why, didn’t I explain that?” asked Mr. Pauling. “Must have slipped my mind when relating the story yesterday. The prisoner told us how they managed. The submarine never entered any port—unless you consider the hiding place of the chief of the gang a port—but picked up her cargoes in mid-ocean.”

“Oh, I see, transferred them from another ship, eh?” said Rawlins. “Stupid of me not to think of it.”

“Not quite right yet, Rawlins,” chuckled Mr. Pauling. “It was this way. A vessel would sail from a West Indian port with a cargo and would drop it overboard at a designated spot. Then the submarine would pick it up. If they had transferred on the surface they might have been seen and rough weather would have interfered. Moreover, if those on the schooners saw the submarine or knew of her they might have talked. They imagined the things were to be grappled or brought up by divers. The head of this bunch takes no chances.”

“Ah, now I see a light dawning!” exclaimed Rawlins. “I think that solves several puzzles. You remember those messages you boys heard? Well, they always, or nearly always, included numbers—‘thirty-eight fifty, seventy-seven’ was one, I believe—and ‘good bottom’ and similar things. I often wondered about those, but I’ll bet those were the spots where the sub was to find cargoes dumped. Hasn’t that Russian Johnny come across with anything more about the high Muck-a-Muck of the bunch and where he hangs out?”

“No, I had another long session with him, but he swears he knows nothing about it and for once I am inclined to think he is telling the truth,” replied Mr. Pauling. “He insists that he never visited the place—never saw the chief and does not even know who he is—except that all spoke of him as of a supreme being or a king. His story is that only a few men—just enough to man the submarine—including the fellow who died, went to headquarters. That the others, including himself, were always put ashore at a small island in the West Indies where they had a camp and that they walked to the island from the submarine and from the shore to their under-sea craft in diving suits.”

“That’s a probable yarn,” assented Rawlins. “Did he tell you the name of the island?”

“He says he doesn’t know it himself, that there were a few natives there when he first arrived, but that under orders from their superiors they murdered the blacks in cold blood.”

“Dirty swine, I’ll say!” exclaimed Rawlins. “Well, I know the West Indies a lot better than I know New York and if we can squeeze some sort of a description from old pig-eye I’ll wager I can locate that hangout. But now about that other business—those messages—have you got the notes you made of them, boys?”

“Sure,” replied Tom, “At least, Mr. Henderson has. We gave them all to him.”

“Well, we’ll need ’em if Mr. Pauling thinks my proposition all right,” said Rawlins. “I hadn’t got it quite settled as to details when I came in, but the capture of that sub—if she is the one—has cleared it all up.”

“I can tell you better what I think of any proposal you may have after I have heard it,” said Mr. Pauling.

“All right, here goes,” laughed Rawlins. “You see from what you told us about that dead fellow’s confession, I am pretty sure the big ‘I am’ of the bunch is hanging out somewhere in the West Indies. You said he was giving you the place and had mentioned three figures of latitude and longitude when he kicked off. Now I don’t know what those figures are, but there are not such an everlasting lot of combinations of figures in the islands—that is, where a man could have a secret hangout—and I know ’em like a book—better than any book in fact—and if I had those figures I’ll bet I can locate the old Buckaroo. Not only that, but with my suits and the boys’ radio and my submarine chamber—the same as I use for taking under-sea pictures—we could get the loot and everything else if he’s got any of it under water.

“I rather figured, from what you said, that might be where he’d hide it, especially as he seems stuck on under-sea work. Why, if the old cove himself had a house under the sea I could find him! If they used this new-fangled radio under water up here you can bet your boots the old guy’s using it where he hangs out and if we’re any place near we can pick him up and the boys can locate him with that radio compass business. You see he probably won’t be wise to any one else being on to the radio business. I was afraid that sub might get back and give it away, but the chances are that if the men aboard her got ashore they either won’t dare show up down there and will just fade away or else we can beat ’em to it.

“Taking that sub gave me another idea and a good one. We can fix up the old boat and go scouting for old Stick-in-the-mud in that. If he or any of his gang see her they’ll think it’s all right and that their gang’s still in her. I know a pretty good lot about handling a sub and we can pick up a few good ex-navy men I know. Now don’t you think that’s a corking good scheme, Mr. Pauling?”

Mr. Pauling hestitated, thinking deeply, before he spoke.

“It has its good points,” he admitted at last, “but it’s rather a wild scheme—just what I should expect from a boy who’ll tackle two strangers and a submarine single-handed under water—and there’s not one chance in ten thousand that it will succeed. You see, the West Indies are a pretty good-sized place and you’d have to go by guess work a great deal, even with the figures the man gave us. However, I’m willing to aid and abet the scheme, as any chance—no matter how remote—of getting that arch fiend is worth trying. I can get the submarine without trouble and can secure men who can be depended upon, but who’s going with you on your wild-goose or wild-man chase?”

“Why, we are!” cried Tom and Frank in unison.

“The dickens you are!” exclaimed Mr. Pauling. “I should say not!”

The boys’ faces fell. “Oh, Dad, please let us go,” begged Tom. “It will be great—going in a submarine and trying to find that fellow with our radio. Why won’t you let us go?”

“Too much risk,” replied his father. “I’ve had one fright over you and that’s enough.”

“Well, that rather knocks out my plans, too,” declared Rawlins. “I’d counted on the boys going to work the radio end of it—seems kind of hard on them to let some one else do it after they invented the thing and were responsible for getting the men and the sub. If it hadn’t been for them I’d never have got ’em, as it was their hearing Tom yell for help that made ’em surrender, and you’d never have thought of that block and the garage if they hadn’t located those messages with their radio compasses. I don’t think there’s any danger, Mr. Pauling.”

“I don’t agree with you,” declared Mr. Pauling in positive tones. “If you go after that man there’s every danger. You can’t tell what force he may use or how an attempt to capture him might turn out.”

“But I had no idea of attempting to get him alone,” replied Rawlins in surprise. “My plan was to have a trim little destroyer right handy and then, when we’d located Mr. Big Bug, we’d report to the jackies and let them do the dirty work. The boys wouldn’t have to be where there was any scrapping going on and that old ex-German sub is never going to be my coffin if I can help it, I’ll tell the world. No, sir, my idea was just to do the scouting, so to speak—secret service under the sea—and let the boys be in on the preliminary intelligence work running the secret service of the air as you might say.”

“Well, I suppose in that case there would be little risk,” admitted Mr. Pauling, “and as you say, they are really the ones who should be allowed to have charge of their own apparatus as they have earned the right to it. I’ll have to give a little more consideration to the matter before I decide, however. Possibly I may wish to go along also—or I may be asked to, when I put this matter before my superiors. Now here are those figures given by the dying man and the notes made by the boys.”

Unlocking a drawer, Mr. Pauling took out a packet of papers and spread them before Rawlins, while the two boys, now that events had taken a more hopeful and promising turn, laughed and talked excitedly to each other, wildly enthusiastic at the bare possibility of going on the unique search.

For a few minutes Rawlins studied the various sheets intently and silently, comparing the figures which the boys had heard spoken and the ones given by the dying Irishman, and at last he glanced up.

“These numbers of the boys’ will need a lot of study,” he declared, “but these the chap in the hospital gave are dead easy. One of ’em is nineteen and as there’s no longitude nineteen in the West Indies, or within two thousand miles of the islands, it must be latitude, so there we have a clue right out of the box—nineteen north latitude. Now if we take a map and follow along nineteen we’ll know it must be within a few miles of it that we’ll locate old Beelzebub. It can’t be over sixty miles north of that meridian or the man would have said twenty instead of nineteen, and it can’t be south of it or he’d have said eighteen and something. So we can be dead sure the old duck hits the hay somewhere in a sixty-mile belt bounded by meridians nineteen and twenty. Now here are the other two numbers—sixty and seventy-five. You say he sort of lost consciousness between these and you thought he said southwest by south. Well, sixty might be longitude—the sixtieth meridian is in the West Indies—but he might have meant sixty anything and so, if it is longitude he was getting at, it brings us down to a space six hundred miles east and west and sixty miles north and south—quite a considerable bit of land and water to search—about 36,000 square miles—but only a little of it’s land, so it don’t cut such a figure. That’ll take in—let’s see—some of the Virgins, I think, and a lot of little cays and quite a bit of Santo Domingo, but shucks, that’s not such a heap. But I’ll admit this seventy-five gets my nanny. It’s not minutes—’cause there are only sixty minutes to a degree and it’s a dead sure cinch that it’s not latitude or longitude if those other numbers are, and if it’s latitude it would be in the Arctic instead of the Caribbean and if it’s longitude it’ll knock calculations out for about a thousand miles and will take in all of Santo Domingo and Haiti, a bit of Cuba and most of the Bahamas. Looks as if we might have some jaunt. And I don’t get those compass bearings. However, maybe when they get that sub in and search her we’ll find some chart or something. When do you expect——”

At this moment the telephone rang and Mr. Pauling answered.

“Ah, fine!” he exclaimed. “Expect to be in within an hour! Yes, I’d be glad to. I’m bringing some others with me—Mr. Rawlins and the boys. Yes, queer we were just talking of it. Good.”

“It was the navy yard,” explained Mr. Pauling as he hung up the receiver. “They say the submarine is coming in now and will be at the yard in half an hour. The Admiral wants me to be on hand to board her as soon as she arrives and I’d like you and the boys to come along.”

“Hurrah!” yelled the two boys. “Now we’ll see what they had on her.”

“And we’ll know if she’s the right sub,” added Rawlins. “Though it’s dollars to doughnuts that she is—it’s not likely there’s more than one lost, strayed or stolen sub knocking about in these waters.”

When they reached the Navy Yard the submarine was just being docked and twenty minutes later they were entering her open hatch. The boys had never been within a submarine before and were intensely interested in the machinery, the submerging devices, the air-locks and the torpedo tubes, but their greatest interest was in the radio room. But here, much to their chagrin and disappointment, they found practically nothing. There were a few wires, some discarded old-fashioned coils, some microphones and receivers and a loop aËrial. Everything else had been removed and nothing was left to show what sort of instruments had been used. The boys were about to leave when Tom noticed something half-hidden under a coil of wire, and, curious to see what it might be, pulled it out.

“Gosh!” he exclaimed as he saw what it was. “These chaps were using that same single control. This is part of it. Look, Frank, the dial is just the same as the one Mr. Henderson gave us.”

“Gee, that’s right!” agreed Frank. “But then,” he added, “after all it’s not surprising. You know Mr. Henderson said the one he gave us came from a German U-boat.”

“Not a thing in the radio room,” announced Tom, as the boys rejoined Mr. Pauling. “Everything’s stripped clean, but they used the same sort of tuner that Mr. Henderson gave us. Where’s Mr. Rawlins?”

“Somewhere under our feet,” laughed his father. “He went down to examine the hull. Wants to be sure this is the same boat.”

A few moments later the door to the air-lock was opened and Rawlins appeared.

“I’ll say it’s the same old sub!” he exclaimed. “There’s a dent in her skin near the stern on the port side. I noticed it before and it’s there all right. Found anything up here?”

“No, nothing of any value to us,” replied Mr. Pauling. “The boys say the radio’s been stripped from her and we haven’t been able to find a chart or a map or a scrap of paper aboard. We found two of those carriers though—the cigar-shaped affairs you saw the divers towing through the water; but they’re both empty. If these fellows took anything from the garage they disposed of it before they left the submarine.”

“Were the boats on her when they found her?” asked Rawlins.

“No, no sign of them,” replied the officer who was with them. “I boarded her first thing, but there was no sign of life aboard and no boats.”

“It’s darned funny!” commented Rawlins. “If these lads took to the boats they did it deliberately and took mighty good care to clean the old sub out before they left. That disposes of the theory that they were compelled to leave. Do you know what the trouble was with her machinery, Commander?”

“Haven’t found out yet,” replied the officer. “We’ll have the engineers aboard as soon as Mr. Pauling is through inspection.”

“Didn’t see any signs of small boats near where you found her, did you?” inquired Rawlins.

The officer shook his head.

“No,” he replied, “but it was pretty dark and they might have been within a few miles—very low visibility.”

“And no other vessel that might have picked them up?” continued Rawlins.

“Not a sail in sight—except a fishing smack about ten miles off. We ran down to her and boarded her. Thought they might have sighted the sub, or picked up the men. They hadn’t done either. Bunch of square-heads that didn’t seem to know what a sub was, just dirty fishermen.”

“Dead sure they were?” asked Rawlins. “Didn’t notice where she hailed from, did you?”

The officer flushed.

“Afraid we didn’t,” he admitted, a trace of resentment at being questioned in his tones. “She hoisted sail soon after we left her.”

“And nothing peculiar about her in any way, I suppose?” suggested Mr. Pauling.

“Well, I didn’t see anything,” replied the commander, “but I believe one of my bluejackets made some remark about her rig. He’s a bo’sun’s mate and an old man-o-warsman—Britisher but naturalized citizen and served in the British navy. Would you like to question him? I’m no expert on sailing craft myself.”

“Better talk to him, Rawlins,” suggested Mr. Pauling.

As there seemed nothing more to be discovered on the submarine the party left the under-sea craft and walked to the destroyer which had found her. The sailor to whom the officer had referred proved to be a grizzled old salt—a typical deep-sea sailor and the boys could not take their eyes from him. Touching his gray forelock in salute, the man hitched his trousers, squinted one eye and reflectively scratched his head just over his left ear.

“Yes, Sir,” he said, in reply to Mr. Rawlins’ question. “She was a bit queer, Sir. Blow me ef she warn’t. Man an’ boy Hi’ve been a sailorin’ most thirty year an’ strike me if Hi ever seed a Yankee smack the like o’ her, Sir. What was it was queer about her, you’re askin’ on me? Well, Sir, ’twas like this, Sir. She had a bit too much rake to her marsts, Sir, an’ a bit too high a dead-rise an’ her starn warn’t right an’ her cutwater was diff’rent an’ her cuddy. She carried a couple o’ little kennels to port and sta’board o’ her companion-way, Sir—same as those bloomin’ West Hindian packets, Sir. An’ as you know, Sir, most Yankee smacks carry main torpmas’s and no fore-torpmas’ while this e’er hooker was sportin’ o’ sticks slim an’ lofty as a yacht’s, Sir, an’ a jib-boom what was a sprung a bit down, Sir. But what got my bally goat, Sir, was the crew. Mos’ of ’em was Scandinav’ans, Sir, but the skipper was a mulatter or somethin’ o’ that specie, Sir, an’ blow me hif he didn’t talk with a haccent what might ha’ been learnt at Wapping, Sir.”

Rawlins whistled.

“I’ll say there was something queer about her!” he exclaimed. “Anything else? Did you note her name and port?”

Once more the old sailor scratched his head and shifted the tobacco in his cheek before replying.

“Cawn’t say as how Hi did, Sir,” he announced at last. “You see, Sir, she had her mainsail lowered, Sir, and a hangin’ a bit sloppy over her stern, Sir, an’ we was alongside an’ didn’t pass under her stern, Sir.”

“What sort of boats did she carry and how many?” asked Rawlins.

“Dories, Sir, six of ’em,” replied the sailor, “anything more, Sir?”

“No, I think that’s all. Thanks for the information,” replied Rawlins and then, reaching in his pocket he handed the man several cigars.

Touching his forelock again and with a final hitch of his trousers the sailor turned and strolled off with the rolling gait of the true deep-water seaman.

“Well, what do you make of it?” asked Mr. Pauling, when the sailor was out of earshot.

“I’ll say it’s blamed funny that packet was hanging around near the sub,” replied Rawlins. “It might be a coincidence—Bahama smacks do come pretty well up here during the summer—and she might have been a rum-runner, but putting two and two together I’d say she was waiting for the sub and that the crew were on board her when the destroyer came up.”

“Jove!” ejaculated Mr. Pauling. “Then you think she was a West Indian boat?”

“I don’t think, I know!” answered Rawlins. “A Bahama schooner—not any doubt of that. Only Caribbean craft carry those two deck-houses and that sprung jib-boom and the darkey skipper with the English accent just clinches it. I’ll bet those square-heads were Russian Johnnies or Huns off this darn sub. Say, if we don’t get a move on they’ll beat us to the islands yet!”

“Gosh!” exclaimed Tom. “I’ll bet they took their radio outfit aboard.”

“I’ll say they did!” declared Rawlins. “And like as not they’ll be under full sail for the Caribbean by now and working that radio overtime to get word to the old High Panjandrum down there.”

“Not if I know it!” cried Mr. Pauling. “Come along, Rawlins. I’m going to see the Admiral.”

The result of that hurried and exceedingly confidential interview was that, as the boys and Mr. Rawlins were crossing the Manhattan Bridge in Mr. Pauling’s car, they looked down and saw a lean, gray destroyer sweeping down the river with two others in her wake, black smoke pouring from their funnels, great mounds of foam about their bows and screeching an almost incessant warning from their sirens as they sped seawards bearing orders to overhaul and capture a Bahama schooner that, under a cloud of canvas, was plunging southward on the farther edge of the Gulf Stream, her mulatto skipper driving his craft to her utmost, while aloft two monkeylike negro seamen were busily stretching a pair of slender wires between the straining lofty topmasts.

Two days later, a black-hulled liner steamed out from New York’s harbor and dropping her pilot also headed southward for the Bahamas. Upon her decks stood Tom and Frank with Mr. Pauling and Mr. Henderson by their sides, while in the Navy Yard, with a marine guard tramping ceaselessly back and forth about her, a submarine was being feverishly fitted for a long cruise.

After much discussion, Mr. Pauling had at last given consent to the boys joining in the search for the mysterious master mind whose plans had so far come to grief through their efforts, although he refused to consider letting them go south on the captured submarine. But the boys had no objections to this, for they did not look forward with any pleasure to an ocean voyage in the sub-sea boat and were filled with excitement at the thoughts of the adventures in store for them when they joined Rawlins, and the submarine at a prearranged meeting place in the Bahamas.

As they watched the skyline of New York fade into the mists of the summer afternoon and the smooth gray-green sea stretched before them beyond the Narrows, they were thinking of the adventures which had so strangely fallen to their lot in the great city and Tom chuckled.

“Remember when we first called ourselves radio detectives?” he asked Frank, “Gosh! we never thought we’d even strike anything the way we did.”

“You bet I do!” rejoined Frank. “Say, wasn’t Henry sore because he couldn’t go and wasn’t he crazy to find out what we were going for? It’s great! And we’re real radio detectives now—working for Uncle Sam, too!”

“Rather, I should say, ‘radio secret service,’” said Mr. Henderson who stood beside them. “But don’t talk about it. Remember the first thing for a person in this service to learn is to hear everything, see everything and say nothing.”

“We will!” declared the boys in unison.

“That’ll be our motto!” added Tom. “Isn’t it a bully one?”

“As Mr. Rawlins would say, 'I’ll say it is’!” said Frank.

THE END

BY A. HYATT VERRILL

D. APPLETON AND COMPANY

Publishers, New York