"They're a noble lot, then," grunted Jack, disgustedly.

Mr. Hennessy proposed that they go down to have a look at the dungeon underground. While they were examining that damp, slimy old cell, the conversation continued.

"Has either of that pair seen you, Mr. Graham?" asked Jack.

"I don't believe it. I'm not stopping at the Hotel Clayton."

"Then neither of them will suspect that I've been posted," muttered Benson, with a short laugh.

"Why do you say that?"

"Because I rather think," smiled the young submarine captain, "that I may attempt to pay that pair back in their own coin—somehow. By the way, do either of them know you well when they see you?"

"They might remember me as a newspaper writer," replied Graham. "So I'll keep out of the way."

"It won't be necessary for me to keep out of the way," added Hennessy. "I don't know either Mlle. Nadiboff or her companion; and, besides, I'm here openly as a reporter interested in the submarine craft."

By this time the three had returned to the upper air.

"I'll vanish, now," proposed Mr. Graham. "But you, Hennessy, if Captain Benson doesn't mind, might as well go along with him. You may get a good look at the Nadiboff woman. You, too, may think her very young. She has a knack of keeping so. Yet she's at least twenty-eight or thirty. Good-bye, for the present!"

Graham turned, losing himself from their sight amid the ruins. Hennessy walked with Jack back to where Hal and the woman awaited them.

Jack's mind was rapidly revolving plans for teaching some one a lesson that would not be forgotten.



CHAPTER VIII

EVEN UP FOR MR. KAMANAKO

"This is Mr. Hennessy, one of the newspaper men who visited our boat yesterday afternoon," said Jack, on rejoining his companions. "Mr. Hennessy has been returning good for evil. While I am unable to tell him any of the things he wants most to know about our boat, he, on the other hand, has been telling me much of interest about these ruins."

"There are a lot of legends about this old wreck of a castle," laughed Hennessy. "Most of them are too silly to consider for a moment. One of the old stories has to do with a secret passage. Some of the guides hereabouts show what they solemnly explain was one of the outlets of the secret passage in bygone days. Do you care to devote five minutes to looking at the ridiculous thing?"

Mlle. Nadiboff smilingly accepted the suggestion, so Hal and Jack also agreed. The reporter led the way across a field, pausing at last before a fringe of weeds and low bushes.

"Now, just step through this wild hedge," Hennessy proposed, smilingly, "and you'll see how little it takes to start a yarn. Look out, though, that you don't fall down."

As they stepped through the fringe cautiously the members of the party found themselves peering down the shaft of what appeared to be a very ordinary well. It was circular, in shape, and had been laid, on the inside, with a masonry of stones.

"There is water at the bottom, isn't there?" inquired the woman Spy.

"Yes," replied Hennessy. "It was never anything more than a well. Yet, day before yesterday, one of the local guides brought me here and insisted on telling me all about its having been an outlet of a famous secret passage from the castle. I had some fishing tackle in my pocket, so I rigged up a line and weight, and let it down. I satisfied myself that there were about four feet of greenish, slimy water at the bottom of a well. I wish you could have seen the guide's face!"

"Here come some visitors, now," nudged Hal.

Two men and four women, led by a guide, approached the place.

"This shaft looks dark and mysterious enough," began the guide, reeling off a well learned lesson, "to be as full of historic interest and mystery as it really is. This shaft is what is left of one of the outlets of the famous secret passage to and from the castle."

While the new visitors crowded about, asking questions and offering remarks, the party that Hennessy was guiding stepped into the background, secretly enjoying the guide's buncombe.

"If people would only stop to use their good sense a bit," whispered Hennessy, "they'd know, at once, that the shaft is only a long disused well."

"Great Scott!" whispered Jack. "Here come Mr. Farnum and Eph with a guide. Let's see if they will be buncoed."

Guide number two came up, with the shipbuilder and Somers in tow. Greetings were exchanged. Then the last arrived pair stepped forward in the guide's wake. Farnum listened with an amused smile.

"Oh, pshaw!" grunted Eph. "Is this the best you can show us? This is nothing but an old well, with ten feet of malaria at the bottom. Show us, for a change, something that we can believe."

Hal began to laugh quietly. Then all hands stepped forward for another look down the shaft. As they stepped outside again Benson happened to turn just in time to see a familiar figure coming along a path near by.

It was Kamanako, better dressed than he had been earlier in the morning, and carrying a bulging dress suitcase.

"Hullo!" muttered Jack Benson, in a tone loud enough to carry to the ears of the newcomer. "There's that infernal Jap spy—that scoundrelly thief of other men's secrets!"

Kamanako halted as abruptly as though he had been challenged by a sentry. As he saw the young captain a dark, red flush crept into the cheeks of the little, brown man.

"You talk much," sneered the Japanese his anger rising.

"I say what I think about spies and fellows who would steal other men's secrets," retorted the young submarine captain.

"You will hold tongue better, if you please," snapped Kamanako.

"I? Hold my tongue for any scamp like you?" taunted Jack Benson.

The taunt had the effect for which Jack wished. Kamanako, looking furious, dropped his dress suit case and ran angrily forward.

Just in time, as the Japanese bounded through the fringe of weeds, Captain Jack dodged adroitly to one side.

So Kamanako plunged past him—and, the next instant, there came a smothered yell from the inside of the well shaft.

"Oh, that was a shame!" came indignantly, from one of the women in the party of strangers.

But Jack, paying no heed to her, had stepped back to the edge of the well shaft. Dimly, down at the bottom, he could make out Kamanako, standing in slimy water that reached nearly up to his arm-pits.

"Is the water fine, eh?" Jack called down, laughingly.

"I show you—some time!" came the answer, in smothered rage.

"You showed me Japanese jiu-jitsu," mocked Benson "so I had to do something to return your courtesy. What I have just shown you is called—American strategy!"

By now Kamanako had succeeded in pulling himself part way out of the water, using his hands and feet on projecting bits of the old masonry.

"You'll get out, in time, for you're a patient fellow," Jack called down, in a tantalizing kind of encouragement. "Don't forget the name that I have just given you—American strategy. And, the next time a fellow tries to make you mad, don't let him do it until you've looked the ground over. American strategy—yes, that's the name."

Laughing, as he straightened up, Jack turned away from the shaft

"And aren't you going to throw him down a rope, or do something to help the poor fellow out?" demanded the same indignant woman.

"Not in view of his line of offense, madame," Benson replied, raising his cap.

"Offense? What did he do?"

To the whole party Jack explained how Kamanako, that same morning, had been caught spying upon the controlling mechanisms of the submarine boat. All the young skipper's hearers were satisfied, then, to leave the Japanese there to work his own way out, since no one feels any sorrow over the punishment of a spy.

"Gunpowder and doughnuts! But you did get square," chuckled Eph, as the submarine party turned back to the automobiles.

"So that Japanese was a spy, you said?" murmured Mlle. Nadiboff, in a low tone, as they walked along.

"Yes, beyond a doubt," Jack assured her.

"It must seem strange to be a spy," murmured the young woman. "It must give one a strange feeling."

"Yes, and a mighty mean feeling," agreed Jack, coolly.

As he spoke he raised his eyes carelessly to her face. He did not make the glance so significant as to betray his real thoughts.

Mlle. Nadiboff did not flinch nor change color under that brief scrutiny. Instead, she appeared to be almost lost in thought as she walked along.

Suddenly she clutched at the young captain's arm.

"I wonder if you would do something very great, to please me?" she murmured, questioningly.

"I'd certainly like to have you try me," responded Jack Benson, in an equally low tone. He spoke the truth, too, for he believed that this charming but dangerous companion was scheming some sudden move in her plans as, a spy. He wanted to find out what that move would be. Above all, if it were possible, he wanted to get knowledge of which foreign country she represented.

"Won't you contrive to drive alone with me in my car, when we reach it?" she whispered, coaxingly.

"And leave your chauffeur behind, also?" asked Jack, smiling.

"That will not be necessary. I do not mind him. But I have much that I wish to say to you, my Captain. As for your friend—pardon me, but he is dull, and—"

"Quiet, I think you mean, Mademoiselle," interposed Jack. "Hal's worst enemy, if he had one, would hardly call him dull."

"Anyway, my Captain," murmured the young woman, "he does not interest me, and I do want a few words with you."

"This charming young spy," muttered Benson quickly, to himself, "is beginning to feel that I'm not enough interested to be coaxed away from my duty by flatteries. I take it she means to show her real hand, and try to play it in earnest. If that's the case, I want to know what she is going to say."

Aloud he replied:

"It will be easy enough to send my friend away with the others, Mademoiselle. When we reach the automobile all I shall have to do will be to look straight at him."

"Ah! You have a code of signals—you two?" Mlle. Nadiboff laughed, delightedly.

"A code?" repeated Jack. "No; we have never needed one. But my chum is an unusually bright and quick young man."



CHAPTER IX

"DOG, WHO IS YOUR MASTER?"

Seeing Jack and the young Russian woman so interested in their talk, the others had gradually strolled away from them.

Hennessy had already succeeded in securing an invitation to return to Spruce Beach in Mr. Farnum's hired auto.

Hal Hastings presently turned, as though to step over to Mlle. Nadiboff's car, but he caught a swift look from Jack, and turned back. Hal had not yet heard of the grave suspicion against the young woman, and could not guess what this move of his chum's meant. Hastings, however, was swift to take the hint.

"You have not overstated your friend's intelligence," murmured the young Russian gleefully. "At a short look from you he retreats."

"Oh, Hal and I always understand each other," smiled Jack.

"That is very interesting. And yet I do not like Mr. Hastings as I like you," replied the young woman.

She looked at him with a friendly, little flash in her eyes. Had Jack been a few years older, and not warned, he might have been snared by this experienced flirt. As it was, he did not take the trouble to answer her last little speech.

Just before they stepped into the car Mlle. Nadiboff uttered a few quick words, in some foreign tongue, to her man at the steering wheel. The auto sped away. Jack noted only, at first, that they were now going further from Spruce Beach. The road down which they drove, however, was a beautiful one, and the submarine boy did not much mind where they went, provided he could find out how Mlle. Nadiboff meant to make the approach against his loyalty to the submarine company.

"Do you know, my Captain, that you are hardly a flattering escort?" began Mlle. Nadiboff, after they had whirled along for a mile or more.

"Why not?" Jack inquired, bluntly.

"Have you noticed how I seem to please most men?"

"I saw that several were very anxious dance with you last evening, and that, whenever you were seated, men flocked about your chair."

"Why do you suppose they did that?" challenged Mlle. Nadiboff.

"Because you are a very handsome woman, and the men admired you," Benson answered, plainly.

"Ah! Then you think I am handsome?"

"I haven't a doubt of it," Jack answered.

"Do you admire me?"

The challenge came plain and direct. Mlle. Nadiboff now gazed searchingly into the submarine boy's eyes.

"I—I think you a very handsome woman to look at," Captain Jack admitted, readily.

"Is that all you have to say?"

"I—I am afraid I do not understand you, Mademoiselle."

"You have no desire to be especially gallant to me? It would cause you no jealousy if you, saw that I preferred the company of other men?"

Jack Benson returned her glance, almost in, bewilderment for a moment. Then he leaned back, trying to stifle the impulse to laugh, but he did not wholly succeed.

"You are amused?" cried the young Russian, half angry.

"Amused—yes, at the idea of my falling in love, if that was what you meant to suggest," replied Jack, again speaking very candidly.

"And why should that amuse you, my Captain?"

"Why, do you know how old I am, Mlle. Nadiboff? Or rather, how young? I am only sixteen. At my age, if I formed any notion of being in love, it would be sensible to have me spanked and put on a short diet for a few days."

He laughed merrily, now, and Mlle. Nadiboff turned away her head to conceal the tears of vexation that started to her eyes.

"Bah!" she thought to herself. "I have been wasting time—at Lemaire's orders. The only way to induce this boy to betray his trust will be by offering him presents of marbles, tops, kites—bah! Bah!"

Mlle. Nadiboff settled back in her seat, looking straight ahead, her attitude as frigid as could be. For some moments she did not attempt to speak. When she did open her lips she said, icily:

"I find that I have been wasting my time."

"Wasting your time, Mademoiselle?" echoed Jack Benson, coolly, for he was much more fully alive to the situation, thanks to Mr Graham, than she had any chance to know. "May I ask what you have been trying to do?"

The question made the young woman bite her lip. Mlle. Nadiboff had been a spy quite as long as Mr. Graham had stated. As she looked back over the years she was able to recall man after man whom she had flattered and lured by the witchery of her eyes. Secret after secret she had coaxed from men entrusted with guarding such mysteries. The rewards of the work had kept M. Lemaire and herself both bountifully supplied with money by the foreign governments that they had served as spies. Most men whom she had tried to win into her service the young Russian woman had found easy enough victims. But now, here was a sixteen-year-old boy laughing at her attempts at "cleverness."

"I was wrong to think Jack Benson a fool," she said to herself, angrily. "He is far more clever than the men I have met. I can do nothing with him. I must turn him over to Lemaire—to see if that prince of spies, as he has often been called, can find the flaw in this submarine boy's armor."

With that Mlle. Nadiboff leaned forward, murmuring a few words to the chauffeur, who nodded slightly. Then the young woman leaned back, turning a smiling, friendly but no longer coaxing face to Jack Benson.

"If I have amused you," she smiled, "I am glad. We will say that much and forget the rest, eh, Captain Benson."

"I am glad to agree to anything that will please you," responded the boy, gravely.

Mlle. Nadiboff shot a covert look at his face, then decided to say nothing. She began to have a suspicion that this sixteen-year-old boy was far more clever than she, despite all her years of strange experiences.

A mile further along the automobile branched off the main road, running down a shaded lane at much reduced speed.

"What is this—some short cut back to the beach?" asked Jack, trying to conceal his astonishment.

"Yes," replied the young Russian, falsely.

Soon the big car stopped. The chauffeur thrust a whistle between his lips, blowing a trilling blast.

Jack Benson changed color somewhat. This sounded suspicious—a signal in the woods. It was doubly suspicious after the hints that Mr. Graham had given the young submarine captain.

"Do not jump—do not be afraid," laughed Mlle. Nadiboff, rather maliciously. "Nothing in the way of danger threatens."

Almost immediately the chug-chug of another auto was heard, just ahead up the narrow road. Then into sight glided a small runabout, which sat M. Lemaire, all by himself. That Frenchman stopped his car, next waving one hand gayly to those in the larger car.

Then, lifting his hat most courteously to the young woman, M. Lemaire stepped over to the other car. The Russian woman spoke in some tongue, the like of which Benson had never heard before. It was Arabic, a language that both of these spies understood perfectly. What she said was:

"The boy is yours. Do what you can with him. I admit that I have failed. I have no hope of being able to do anything with him."

M. Lemaire's eyebrows contracted briefly, in a slight frown. Then, forcing a pleasant look to his face, the Frenchman asked, in a tone easy enough with courtesy:

"Captain Benson, will you step out and talk with me a few moments? I have much to say."

"I can listen," nodded Jack, looking steadily, shrewdly into the eyes of this male spy. "At the same time, sir, this whole proceeding, meeting, request and all are so unusual that I think you cannot do better than to give me a frank explanation of what this all means."

"Means?" murmured the Frenchman, as though not comprehending.

"Yes," retorted Captain Jack Benson, disdaining to beat about the bush for an instant. "If you pretend that you do not understand me, sir, I shall feel obliged to have a poor idea of either your honesty or your intelligence."

"Are you trying to insult me?" asked the Frenchman, a warning flash in his eyes.

"Not at all," Jack answered, unhesitatingly. "I am asking you for a direct statement. Why am I brought here in this fashion? What is wanted of me?"

The young captain was now paying no attention to Mlle. Nadiboff. She, finding herself not needed in the talk, had slipped out at the other side of the car, and was now strolling slowly some yards away.

"Won't you step out, Captain Benson, so we an walk and talk this matter over?" again insisted the Frenchman.

"Then you have something to say that you don't think quite proper for the chauffeur to hear?" demanded Benson, almost mockingly.

"Oh, our good Gaston is all right," laughed the Frenchman, nodding at the chauffeur.

"The chauffeur, then, is one of the crowd—all spies," flashed through Jack's vengeful mind. "I might have guessed it. And this crowd have me a long way from my friends."

"You are not afraid to step down to the ground, Captain Benson?" asked the male spy, half mockingly.

"Afraid?" flushed Jack, springing down to the ground and confronting M. Lemaire. "No; I am not afraid of a regiment like you!"

"I begin to imagine that you are a brave young man, Captain," assented M. Lemaire, rather admiringly.

"Brave?" echoed Benson. "There's nothing here that calls for bravery, is there?"

"No-o-o," smiled the Frenchman slowly. "Nothing, Captain, but the courage to do and dare—and prosper."

"You speak like the puzzle page in a mail order magazine," laughed Jack Benson, more easily. "Now, Monsieur, won't you oblige me by becoming more definite?"

"What can I say, then?"

"Why, M. Lemaire, I always like to deal with people who are direct and right to the point. You plainly have some kind of a scheme that you are trying to put through with me. Won't you oblige me by coming straight to the very point?"

"I shall be as direct as you can wish, Captain Benson," replied the Frenchman, regaining his smile. "Let us stroll. Walking often helps the flow of language."

Out of the corner of his eye Jack noted that, though Mlle. Nadiboff refrained from joining them, she none the less hovered at no great distance from them.

"Now, my young friend," began the Frenchman, after a pause of a few moments, "you command the submarine boat, and you know all her secrets. You are a draughtsman, to, no doubt?"

"A fair draughtsman," nodded Jack.

"You could draw us a model of the boat you command. You could make drawings of all the important parts. You could supply us with explanations."

"Just what sort of explanations?" Jack asked, coolly.

M. Lemaire shot a swift, sidelong glance at the submarine boy.

"How?" demanded the Frenchman. "You do not understand yet?"

"You promised, Monsieur, to be very exact and explicit. What do you want?"

"Why, then, such drawings and such explanations that any skilled shipbuilder, from the plans you furnish us, could build another boat just like, and just as effective, as the boat you now command?"

"What do you want to do with such plans?" asked Benson.

"Why, would you care about that, if I pay you well enough?"

"Perhaps not," muttered Jack Benson. "Still, when I go into anything, I like to know all about it."

"Well, then," cried M. Lemaire, gayly, "first of all, we will come to the question of a fee to be paid you for your trouble. Such drawings and such papers you could prepare for us in two or three days, could you not?"

"I think that very likely," Jack admitted. He had thrust his hands deep down into his trousers pockets, in order to restrain his very natural impulse to spring at the Frenchman and rain blows in the latter's face.

"Two or three days' work, let us say," continued M. Lemaire. "And, for that we will pay you handsomely—ten thousand dollars in the best money of your land!"

They halted, gazing at each other. For a few seconds Jack Benson did not dare trust himself to utter a word. When he did speak, it was to ask, calmly:

"M. Lemaire, who is your master?"

"My master?" repeated the Frenchman. "I do not understand you."

"Every dog, even a dirty one," thundered Captain Jack Benson, "has a master! Who's yours?"

M. Lemaire's face became livid in an instant. His hands working convulsively, he sprang at the young submarine captain.

Mlle. Nadiboff, snatching a riding whip from under her automobile coat, turned and ran toward them. The chauffeur snatched up a wrench, leaping out of the automobile.



CHAPTER X

M. LEMAIRE PROVES HIS TRAINING

"You insult me!" screamed M. Lemaire, halting right under the face of Captain Jack Benson, who looked at him undaunted.

"I didn't," denied Jack. "I let you do that yourself. My congratulations, sir. You certainly know how to insult your own manhood as well as the most confirmed scoundrel could wish!"

"You insult again!" quivered M. Lemaire, his French accent asserting itself. "I s'all make you pay for zat!"

He struck wildly, badly, as a Frenchman does who has no knowledge of boxing. Benson merely warded off the blow, at the same time brushing M. Lemaire back a couple of steps.

"Now, you keep away—Gaston, or whatever your name is!" warned Jack, wheeling upon the chauffeur. "If I lose my temper, some one is going to be hurt."

But that defiance served only to draw the chauffeur on. Raising the wrench, he rushed swiftly at the young submarine captain, aiming a blow at his head.

Just as might have been expected, Jack Benson wasn't there at that instant.

Instead, he dodged nimbly to one side, at the same time driving in a blow that landed under one of the chauffeur's ears. The fellow went to the ground. Swift as a flash Jack bent over him, and snatched up the wrench, hurling it off among the trees.

Then Jack wheeled around to face Mlle. Nadiboff, bowing.

"Don't you attempt to do anything, I beg of you, Mademoiselle," Jack urged. "It would come fearfully hard to have to make even the signs of striking at a woman."

Though she did not fear physical violence from him, there was something in Benson's eyes, at just that moment, which caused the Russian woman to retreat three or four steps.

Now Jack drew himself up, for he was becoming master of himself. He at once resolved to play this game, if there was to be more of it, with greater coolness.

"I think you see, Monsieur, that I am not be frightened by your childish gymnastics," Benson uttered.

M. Lemaire, too, had forced himself to greater coolness.

"Why, Captain Benson, I might even kill, if I found it necessary," replied the Frenchman.

"Then don't get any notion that it's necessary," frowned the young submarine captain. "It would get you into a fearful lot of trouble, and could do you no possible good."

"But you called me a 'dog,'" pursued M. Lemaire, plaintively. "To a Frenchman that is the gr-r-r-rand insult!"

"Let it go at that, then," proposed Benson, with a pretense at amiability.

"Ah! Then you will forget what has just happened, if I will?" cried the Frenchman, eagerly. "That is admir-r-r-rable! Now, then, ten thousand dollars I have said you shall be paid for what you will furnish me. Ah, even in this rich country, one can do much with ten dollars!"

"It wouldn't be much, I'm afraid, as compared with my prospects with the Pollard Company," replied Captain Jack, with his most thoughtful air.

"Your prospects with the company?" echoed M. Lemaire. "Why, my bright young captain, your prospects with the company will continue just the same. They will never know that you have taken this little fortune from me. Ten thousand dollars! Think of that!"

"And you'd turn around and sell what I'd, give you for a half a million, very likely."

"Oh, no, no, no!" disclaimed the Frenchman, solemnly. "There would be nothing like that in it for me."

"Then no foreign government wants very badly to know about the Pollard plans," inquired Jack.

"There is no government that would pay a really great fortune for such information,". M. Lemaire assured the submarine boy.

"There is one," retorted Captain Jack, with a cunning smile.

"Which one?" demanded the Frenchman, doubtingly.

"One that you don't happen to represent," laughed Jack, quietly.

"Ah, I much doubt it, though I beg you to pardon me for saying so, Captain Benson."

"Why man alive," grumbled Jack, "are you running away with the notion that you're the only one who ever approached me with a view to finding out how the Pollard boat runs? You claim, to be a spy for some other government, M. Lemaire. Are you such an infant as to think yourself the only spy in the field?"

"You would have to tell me about the others. Name them, or describe them to me," urged the Frenchman. "Then I would know, if they are real agents of any foreign government."

"I would tell you nothing of the sort," muttered Captain Jack. "I am young, perhaps, yet I'm old enough to keep my own secrets."

"Then it is agreed, anyway," hastened on the Frenchman, "that, in three days, you will have ready the plans and descriptions, and that I, after I have looked them over and have found them satisfactory, will hand you ten thousand dollars."

"If you've made any such agreement," laughed Benson, "then you've made it with yourself only. You certainly haven't made it with me."

"Don't you agree, then?" asked M. Lemaire.

"No," said Jack, shortly, turning on his heel.

"Where are you going, Captain?"

"Back to Spruce Beach."

"On foot?"

"Yes, for I know your kind too well to suppose that you'll offer me a ride back."

"Wait!" cried M. Lemaire, persuasively, and Benson, halted, looking at him. "Of course I cannot offer you a lift back to town," continued the Frenchman, smilingly, "for that would be ungallant. But Mlle. Nadiboff, who had the pleasure of your company out here will, I know, be most delighted at having your company on the return."

"Assuredly," added the young Russian woman, with one of those charming smiles that had failed so utterly with the submarine boy. "I shall feel most offended if Captain Benson does penance by walking all the miles back to Spruce Beach."

"I'd be a fool, then, to take that long walk back, when I can ride," thought Captain Jack.

So he turned, retracing his steps and bowing to the young woman.

"Yet, before we start," proposed M. Lemaire, anxiously, "let us see, Captain, if we cannot yet come to some arrangement."

"Well?" demanded Jack, for boyish curiosity tempted him to find how far this Frenchman was willing to go.

"Captain Benson," proposed Lemaire, "let us say that the price for what I ask shall be fifteen thousand dollars."

"You're not getting anywhere near my price, M. lemaire," laughed the submarine boy, derisively.

"You are playing with me—laughing at me!" cried the Frenchman, yet he spoke cheerily, for now he began to hope that this American boy might yet be induced to sell himself, body, soul and honor.

"We may as well drop this line of talk," hinted Jack Benson. "You were good enough to offer me a ride back to town, I believe?"

"Yet the price? Let us settle that first," begged the Frenchman. "Captain Benson, I will make you one more offer—but it must be the last. Listen!"

Yet that word was followed by three or four utterly mysterious words, uttered in a low voice in Arabic.

"Yes," nodded Mlle. Nadiboff, as Jack glanced from one to the other, "but this must be the last offer."

"The last, the only, the highest offer," muttered Gaston, who had recovered from the blow Captain Jack had given him.

"Well, then, Captain Benson, bring me your plans within three days, with all the other data needed for the construction of one of your submarine boats, and I will hand you, in exchange, the sum of twenty thousand dollars. There you are, my good friend! Twenty thousand dollars. Now you are ours, are you not?"

Disgusted, yet crafty, Jack Benson pretended to hesitate.

"You must give me your answer at once," demanded M. Lemaire. "I cannot be played with any longer."

Captain Jack drew himself stiffly erect, looking the Frenchman full in the eyes.

"M. Lemaire, you must have been a spy for a good many years. You have been engaged so long in dishonest transactions that you are unable to understand such a thing as common honesty."

"Do you call it honesty," demanded the Frenchman, with a bitter smile, "to demand more than twenty thousand dollars for such an easily performed service?"

"You idiot!" broke forth Jack, in sudden contempt. He was no longer able even to play with this rascal. "Your offer is just as good as one of a million dollars would be. I wouldn't take either!"

"What! You have been trifling with me?" demanded M. Lemaire, starting forward.

Now the meaning of those few words in Arabic became plain enough. For Mlle. Nadiboff, who had bent over, her hand toying with the sand, suddenly clutched a handful of the fine grains and straightened up, hurling the sand full in Benson's face.

In that same flashing instant Gaston darted behind the young American. As the half-blinded young captain dodged back, the chauffeur caught him around the neck, dragging him to the ground, while Lemaire sprang a-top of the boy.

Jack fought desperately enough, but the two men rolled him over, struggling to hold his hands. Then—

Click! Snap!

Jack Benson's wrists were handcuffed tightly together.

Now M. Lemaire leaped up, looking down gloatingly at the boy.

"Benson, you young fool," scoffed the Frenchman, "since you refuse to be treated as a friend, you shall know what it is to have us for your enemies. You deem it easy to laugh at us—to call us names! Bah! You will soon be glad to beg from us! Your hours of misery are now before you—perhaps days of torment that shall end in madness. Defy us? Balk our plans? Pouf? How little you know of the people with whom you have now to dealt."

Then, at a sign from Lemaire, Gaston threw himself upon Benson's legs, swiftly binding the ankles together. This done, Lemaire himself added a gag to Jack's mouth that shut off the last chance of making a sound.

This done, the two men bore Captain Jack to the larger auto, while Mlle. Nadiboff, chuckling softly, covered him completely under robes.



CHAPTER XI

JACK'S FRIENDS DO SOME FAST GUESSING

"So that's the kind of people they are?" Jacob Farnum smiled softly as Reporter Hennessy finished repeating the information volunteered by Mr. Graham, the Washington correspondent.

To this Hal had contributed the little he was able to tell of Mlle. Nadiboff's conduct.

"You will have to look to your young captain more closely after this," wound up Hennessy.

"Why?" questioned the shipbuilder.

"Even at this moment he is away in the company of that clever woman."

"Oh, he won't be cross with her," retorted Farnum, with an easy smile. "Jack Benson is always courteous with women."

"But aren't you afraid your young captain will have his head turned by her?" pressed the reporter.

"Who? Jack?" laughed Mr. Farnum. "Say, it's very plain you don't know Jack Benson."

The shipbuilder, two of the submarine boys and the reporter were seated by themselves at one end of the Hotel Clayton's big front veranda.

"Aren't you at all uneasy?" asked Hennessy.

"If I am," proposed the shipbuilder, "I'm going to cure my mental unrest with luncheon. Won't you join us, Mr. Hennessy?"

If appetite were any guide, none of the submarine people felt the slightest uneasiness as to information that the sprightly Mlle. Nadiboff might be able to coax from Captain Jack while on that auto drive.

By the time that the quartette came out again, however, Farnum began to look bothered.

"After two," he declared, "and Jack not here. Now, at three o'clock, I've agreed to take out a party of naval officers from the gunboat. We want to show those Navy fellows some of our prettiest work in the 'Benson.'"

"It looks as though your young captain is finding his companion so pleasant that he forgets to look frequently at his watch," suggested the reporter, slyly.

"Jack Benson doesn't know anything about the three o'clock appointment," replied Mr. Farnum.

"If he isn't here in season," put in quiet Hal, "it won't cause us any real trouble, anyway. Those of us who will be on hand can manage the boat through any ordinary trial or trip."

Eph was very silent—for him. After fifteen more minutes had gone by young Somers sauntered out into the road, where he could command a long view in the direction in which he would naturally look for Jack's approach in Mlle. Nadiboff's car.

After some ten minutes Eph Somers came running up the roadway.

"It's all right," he announced. "The car is coming."

In hardly a minute more the car rolled up to the veranda, and stopped. Mlle. Nadiboff, catching sight of the little party, smiled and nodded graciously as she stepped to the veranda.

"Where's Captain Benson?" inquired Hal, starting toward her.

"Captain Benson?" repeated Mlle. Nadiboff, looking a trifle surprised. "Hasn't he returned?"

"Not yet," Hal Hastings answered her, his gaze fixed steadily on the young woman's face. "How could he return ahead of your car, Mademoiselle?"

"Why, he left me more than half an hour ago, and within two miles of here," replied the young woman, easily. "I proposed going to another hotel, a few miles from here, for luncheon. So he asked me to put him down, saying he would walk in. That was not more than two miles from here, was it, Gaston?"

"Much less than two miles," replied the chauffeur.

"And he hasn't returned?" queried Mlle. Nadiboff, looking mildly curious.

"He has not yet come," Hal replied.

"Then he must be a slow walker, or—but will you take my car and go back to look for him? Will take you to the spot where your young captain left us on foot?"

Hal Hastings's first impulse was to accept the offer of the car. Yet Mlle. Nadiboff's acting was so perfect, her air so unconcerned save for mild curiosity, that any suspicion Hal may have felt for a second or two was quickly banished.

"No, though I thank you, Mademoiselle," he replied. "Captain Benson will doubtless be here before we could make a fair start."

Nodding pleasantly, the Russian vanished through the ladies' entrance. Hal went back to his companions.

"Say," broke in Eph, presently, "if she left Jack to go several miles for her luncheon, she got it and returned mighty quick."

"Probably used a woman's privilege, and changed her mind about driving to that other hotel," suggested Mr. Farnum.

For some minutes more the party waited, then went down into the road, but there was no sign of Jack coming along.

"Mighty strange!" muttered Hal, uneasily. "Well, we've got to aboard, now," announced Jacob Farnum, after glancing at his watch. "Sorry we can't very well invite you to go with us, Mr. Hennessy."

"I shall see you, if you come ashore in the evening," replied the reporter. "In the meantime I shall be about the hotel. If I see Benson, I'll tell him where you all are."

Being well provided with cigars, Reporter Hennessy did not quit the veranda after he had once taken his seat there. So it happened that he noted the arrival of M. Lemaire, alone in a runabout, just about an hour after the time when Mlle. Nadiboff had returned.

Jack Benson, however, did not put in an appearance.

The submarine torpedo boat, with its naval party aboard, sailed out of the harbor, returning just before dark.

Then, as soon as could be, Messrs. Farnum and Pollard and Hal and Eph came ashore, heading straight for the hotel.

"Your young captain hasn't succeeded in walking the two miles' distance to this hotel," announced Mr. Hennessy, who was waiting for them.

"Confound it, I don't like the looks of this," muttered Farnum, uneasily. "It looks as though something had been done to Benson."

"Will you notify the police?" questioned the reporter.

"I don't believe that would be wise. At any rate, not quite yet," interposed Hal.

"Then what would you do?" demanded Mr. Farnum, turning upon the young engineer.

"If Jack has come to any misadventure through that pair of spies," uttered Hal, anxiously, "it seems to me it will be a heap more promising if we keep a sharp, unseen watch over every move made by M. Lemaire and Mlle. Nadiboff."

"Right-o, every time!" clicked Eph. "If anything has happened to good old Jack through that pair, then they're the only ones to be watched!"

Dinner, that evening, wasn't as confident a meal for the submarine party as luncheon had been. Both Mlle. Nadiboff and the Frenchman were in the dining room, though they did not sit together.

Later, the young Russian woman appeared in the ballroom. She was as eagerly sought as a partner as she had been the night before.

Farnum and his friends did not enter the ballroom, not having brought evening dress ashore with them.

Yet, some of the time, they remained near the entrance to the ballroom. It was here that M. Lemaire, in evening clothes, saw them and bowed most amiably.

"You do not care for the gaiety of the dance?" he inquired.

"No," replied Jacob Farnum, evasively. "We are looking for Captain Benson, and thought it just possible he had entered the ballroom."

"Did he not tell you, this afternoon, whether he would be at the dance?" Lemaire inquired, in a tone of polite curiosity only.

"We didn't see him this afternoon," replied Mr. Farnum, rather curtly.

"You astonish me," cried the Frenchman.

"In fact we have not seen Captain Benson since we left him on an automobile ride this morning."

"Ah! I had not heard of that," murmured the Frenchman. "I trust nothing is wrong with the gallant young fellow."

"Oh, that's hardly likely," drawled Jacob Farnum, with an effort. "Captain Jack Benson a lad with a pretty good idea of how to take care of himself."

While speaking Farnum did not look particularly at the Frenchman, but trusted to the boys to watch the man's face covertly. M. Lemaire, however, proved to be a good actor and a master of facial expression.

As soon as he could, without attracting attention, Jacob Farnum drew his little force to one side.

"Something serious has happened to Jack," muttered the shipbuilder, moodily. "It may have been an accident, but I believe it's ten times more likely that that infernal gang of spies have trapped the lad and brought harm to him. We've got to act, and act fast!"



CHAPTER XII

IN THE POWER OF THE SPIES

Something had, indeed, "happened" to Jack Benson, and much more was likely to happen.

The young submarine captain lay on a pile of dried grass that had been thrown on a board floor. His hands were still manacled. Worse, one of his feet now had an ankle-ring fastened securely, and this was chained to a stout staple driven in the floor.

It was a curious place in which young Benson lay, a place with a strange history.

Years before a tunnel had been bored into the side of a hill. After the tunnel had been lined with a masonry of stone it was not more than three feet in diameter. This tunnel led into an artificial cave some eighteen feet square and nine feet high. This cave had been shored up and boarded as to ceiling, floor and walls.

A great deal of labor had been expended in building this curious place under a low hill. Yet the original builders had figured that their time so spent would yield large returns. This part of the Florida coast lay conveniently near to Cuba. On moonless nights a small sailing craft would put in along the coast, laden with smuggled Havana cigars. There being no safe place along the shore in which to store the cigars, this place, hidden well in a forest, had been constructed as a safe depository. For some time the cigar smugglers had prospered. Then, as was to have been expected, Uncle Sam's sharp eyed customs men ran the illegal business down, arresting the smugglers, all of whom were subsequently imprisoned.

For a while afterwards this cave had been visited by the curious. All this smuggling, however, was now a thing of many years past, and curiosity-seekers had come to leave the place alone.

M. Lemaire, however, in studying the surrounding country, had heard of the artificial cave. He visited it. At need, he saw that it would suit his purposes. And now Jack Benson lay there, having been brought hither in Mlle. Nadiboff's automobile.

The young submarine captain was now not gagged. He had yelled for help perhaps two hundred times in the long hours since his enemies had left him there. Yet there had been no response. Benson was now willing to believe that there was now no likelihood whatever of his being able to summon help.

Unable to consult his watch, and lying there in complete darkness, the submarine boy had lost track of time. It was now nearly two in the morning. He had not eaten since early the morning before. He was famished, and, what was much worse, was parched for want of a drink of water.

"I wonder if they intend to leave me here to die?" thought Jack Benson, for perhaps the five-hundredth time. "It would be fiendish. Yet looking for mercy in Lemaire would be like looking for a lake of pure water in the Sahara."

Jack shifted, as much as the chain at ankle would permit. He groaned with the discomfort of it all.

As if in answer there came another groan, low, hollow, yet unmistakable. Captain Jack raised himself on one elbow, listening keenly. The groan was repeated.

"Who's there?" he called.

By way of answer there came still another groan. It was hollow, gruesome, and suggested the grave itself. But Jack Benson was a healthy, intelligent boy, with sound digestion and well tuned nerves.

"If you're trying to work any ghostly trick on me," called Benson, derisively, "try something else!"

Again the groan, a bit louder, but Jack's answer was a merry, ringing laugh, in which there, was not a trace of dread.

"Thank you for the company, Mr. Groan," he called cheerily. "I was beginning to feel a bit lonely. But say! Can't you bring a light—even a ghostly one?"

"I am the spirit of Paul Jones," breathed a low, wailing voice.

"Oh nonsense!" jeered Jack. "Paul Jones never spoke with a cheap French accent."

"I come to—to warn—you," sounded the same sepulchral accents.

"Bring the warning right in and let's have look at it," begged Jack, heartily. Some convulsive sobs sounded out by the passageway.

"Oh, say," chuckled Jack, "as a vender of blood curdling noises you're in need of repairs. Listen! I'll sound a much better line for you!"

With that, and in a deep, blood curdling voice, Captain Benson started in on the first verse of "Down among the dead men."

He was interrupted then by a more tangible sound. Beyond, a match was scratched. Then a lantern was thrust in from the low tunnel, followed by the appearance of the rather long body of Gaston, the chauffeur.

"I thought my singing would bring something," chuckled Jack. "In a large town it always brings the police. Well, how are you? I'm really glad to see anything human, and I suppose you'll answer to that description, eh?"

In silence the chauffeur stepped forward resting the lighted lantern on the floor a few, feet from the boy. Then the Frenchman seated himself on the boards, next bringing out a paper package from one of his pockets. As he untied the string Jack watched with lively interest.

"Sandwiches, eh?" chuckled Jack. "Thank you. I'm ready."

"This is my supper," answered Gaston, taking a bite of one of the sandwiches. "You don't get any."

"Oh, I don't?" demanded Captain Jack, feeling the pangs of hunger worse than ever.

Gaston's next move was to take a bottle from another pocket, uncorking it.

"As you're a Frenchman, I suppose that's wine," muttered Jack. "I don't use that kind of stuff, but water—"

"This is water," replied the Frenchman, pouring a few drops onto the floor before the submarine boy's eyes.

Jack's throat ached at sight of the water. "I suppose you've come here to eat and drink, in order to torment me?" asked Captain Benson.

"It must give you huge pleasure to watch me," suggested Gaston, taking a swallow from the bottle.

"About the only pleasure I could get from watching you," retorted the boy ironically, "would be if I could see you swinging from the end of a rope that was tied in a tight noose around your neck!"

"Perhaps that will happen to you—yet," hinted Gaston, looking keenly at the boy.

"Humph!" muttered Jack. "How would that help your rascally crowd?"

It was plain that the chauffeur didn't really want to eat or drink, but that he had been tormenting the captive. Now Gaston carefully placed the sandwiches and the bottle of water where young Benson couldn't possibly reach them.

"You've been having too pleasant a time here," glared the Frenchman, bending over the boy. "You haven't yet suffered enough to be ready for the plans that we have for you."

With that the chauffeur threw himself a-top of the boy, striking him a blow in the face.

"You lean, long-legged coward!" sneered Jack, angrily. "You know about how much punk you'd have if I had my hands and legs free, and stood before you on even terms. How you'd beg, you wretched craven!"

For answer the chauffeur clutched with both hands at Jack's hair, giving a hard pull. Jack gritted his teeth, panting, until at last the torment forced him to utter a pain-wrung "ouch!"

"Perhaps you will soon learn better than to insult me," leered Gaston.

"You wretched dog," shot back the submarine boy, "you're past insult by any decent man!"

"Careful," warned the Frenchman, "or I will soon make you shriek your apologies to me. I can do what I please with you, and sometimes I have an ugly temper. But listen. I come for one purpose only—to find out what answer am to take to my master, M. Lemaire."

"Take him," retorted Jack, dryly, "the assurance of my undying contempt for him and all of his kind."

"You will be left here another twenty-four hours, without food or drink, if you do not give me a better answer to take," warned Gaston, leering down savagely into the boy's face. "Now, consider! Will you send word that you will be glad to see M. Lemaire in the morning?"

"Yes; if he's going to be in state prison," mocked Benson, "and locked in a cell, as he should be."

"Will you see him here?"

"I can't help myself."

"If M. Lemaire comes, will you be sensible? Will you tell him all that he wants to know about your boat and your work?"

"Not if I'm in my right mind!"

"If you continue stubborn, Captain Benson, you will die here, of thirst and hunger."

"Perhaps," admitted Jack, more soberly. "But it will be a full-size man's death, won't it?"

"Oh, you think, then, that you are not afraid to die of thirst and hunger?"

"Since others have done it," retorted Jack, "I suppose I can, if I have to."

"If you have to?" rasped the Frenchman.

"Do you doubt, then, that we would bring such a fate upon you?"

"I don't believe there's anything too low and cowardly for your crowd to stoop to it," admitted Jack Benson, with spirit.

"Have a care, young man!"

"You asked me a question," growled back young Benson, "and I answered you. If it doesn't suit you, don't ask any more questions."

Gaston regarded the boy with a still more sinister look.

"I think, Captain," continued the chauffeur, "that a little pain—will have a good effect in disciplining you."

Jack Benson did not reply.

"Come, now! Let us see if any of your hair will stay in your scalp?" proposed the Frenchman. "Yet, first of all, boy, have you anything to say that will stop me?"

"If I had, I'd say it," muttered the submarine boy, ruefully.

"Then you might give me that message I asked for."

"Is that all that will stop you?" demanded Jack.

"Yes. All."

"Then go ahead with whatever you have in mind," retorted Jack. "As long as my sane mind stays by me I shall never betray the Pollard secrets to any other government!"

"Let us see, then!"

Once more Gaston fastened the long, sinewy fingers of each hand in the submarine boy's hair. He began to tug, gently at first, but gradually increasing the force of the yank.

Jack Benson stood it as long as he could, then at last let out a yell that was dragged from the depths of agony.

"I'm in time, it seems! Stop that! Now, turn and fight like a man—you contemptible hound!"

It was Hal Hastings's voice that rang through the little cave. Hal had just crawled in through the tunnel. Now, the young engineer, his frame shaking with indignation, stood up at nearly his full length, prepared to spring upon Gaston, who, also, had leaped to his feet.

"I thought it would be worth while to watch and shadow you to-night," jeered Hal, angrily. "It turns out I was right. The bushes planted before the mouth of the tunnel bothered me, a while, in finding the way in here after you—but now I'm here!"

Of a sudden Hal leaped forward, intent upon pouncing on the chauffeur. But Hal's foot caught in a break in the flooring. He pitched and fell forward.

With a snarl of glee Gaston burled himself upon the prostrate body of the second submarine boy, pounding him furiously.



CHAPTER XIII

THE FELLOW WHO SHOWED THE WHITE FLAG

Hal lay face down, and subjected to all the brutal fury of the Frenchman's assault.

For a few seconds young Hastings did all in his power to fight back. He was rapidly losing consciousness, however, and poor Jack lay unable to lend as much as a finger's weight to the defense of his chum.

Then, with an oath in a foreign tongue, Gaston forced Hal's hands back, snapping handcuffs on the engineer's wrists.

"Now, then, you young pest!" snarled Gaston, springing to his feet. "Instead of one of you, I have two. But two shall give me no more trouble than one. So you thought you could subdue me—me, did you?"

"I'd have thrashed you all right," muttered Hal, his senses returning under the storm of taunts, "if my foot hadn't caught and thrown me. You wouldn't dare to free my hands and let me to my feet, just to see what would happen to you! You can't fight—unless all the advantage is handed to you. You're a coward—not a fighter!"

"Careful, my young firebrand, or I'll teach you to be more polite to me," sneered the Frenchman.

"Polite to you?" jeered Hal. "Polite to a spy—to a thief of nations! Polite to a scoundrel who wants to steal the biggest secret of defense that the United States Navy has!"

"Oh, we'll have your secret all right," announced the Frenchman, his voice harsh with triumph. "We now have the two boys who know all about the secrets of the Pollard boats!"

"This sounds so good, I reckon we'd better go right on in, Jerry," broke in another voice.

Gaston started, as did the two submarine boys. Then the chauffeur leaped to the mouth of the tunnel, only to draw back in dismay as a big form emerged and loomed up before his startled vision.

The last comer wore the dress and insignia of a petty officer of the United States Navy.

"Get back there!" warned this big apparition, waving a warning hand that looked big enough to be a ham. "Nobody can't go out until we look into this cargo."

After the big sailor a smaller one crawled out of the tunnel, rising to his feet. Though he was smaller, this second sailor was not exactly what could have been called a little man.

"Now, then," demanded the big sailor, "whose captain of this craft?"

Gaston, his eyes threatening to bulge from his head, had fallen back against the wall opposite. His mouth was wide open, but he ventured no answer.

"Stow my sidelights, Jerry," muttered the big sailor to his mate, "but this is a queer looking hold! And two young men here who'd look like officers of the service, if they wasn't so young."

"There never was anybody more delighted to you," broke fervently from Jack Benson's. "You belong to the 'Waverly'?"

"Aye, aye, shipmate."

"Then you know the submarine, of course?"

"Aye, shipmate."

"I am the captain, and my friend the engineer, of that craft."

The big sailor's reply was an explosive yell.

"Don't let that snake-in-the-grass Frenchman get away, mates," begged Jack, earnestly.

"Jerry, I reckon you can hold the only gang way that opens in on this place, can't ye?" demanded the big sailor, turning to his sturdy looking shipmate.

"I reckon, Hickey," said the other.

"This Frenchman is one of a gang of foreign spies, who have taken this means to force us to furnish plans, drawings and all information about the Pollard submarine boats," Jack continued. "You see how he has us ironed down here."

"Got the keys to them irons, Frenchy?" demanded the big sailor, turning upon Gaston.

"Yes," shivered the fellow, looking yellow with fright.

"Then turn our shipmates loose. Not too much delay about it, either," ordered Hickey.

Gaston obeyed as meekly as a lamb. There was a look in Hickey's steady eyes which would lead one to suppose that the big sailor might be able to use his strength in tearing a worthless human being apart.

"I hope you can understand all the thanks I feel like giving," remarked the young submarine captain, as he rose to his feet, then offered his hand to the big sailor.

"Oh, stow the thanks, anyway," laughed Hickey. "But Jerry and me ain't in for what we thought might be coming to us."

"What was that?" asked Jack, with interest, turning back as he held out his hand to Jerry.

"Why, ye see," nodded Hickey, after glancing down at the Frenchman, who was now unlocking Hal's handcuffs, "I've got a home, a little plantation about two miles back here, that I'm going to settle on for good one of these days. The wife and kids live there. I'd been telling Jerry about the craft and crew, and, as soon as we got shore leave, I took Jerry in tow. We've seen up there two days, and to-night we started back through the woods, 'cause our leave is up at six in the morning.

"Well, while we was coming through the woods we happened to stop a minute. Then we see this Frenchy sneaking through the woods. We wondered what was up. Then he vanished. We looked about, some quiet-like, and on tiptoe, and then we saw this shipmate o' your'n pry apart some bushes and head in this way. It looked queer to us."

"What did you think was up?" asked Jack.

"Why, as near as we could figger, this was some smuggler's hidin' place, and we was figgerin' that perhaps Jerry and me would have five 'hundred or a thousand dollars' reward to divvy up on. It wa'n't—but, anyway, Jerry an' me are proper glad we stumbled in on this, just the same. Now, mate, spin yer own yarn."

Hal was on his feet, by this time, and shaking hands with the two rescuers. Gaston, at the furthest end of the little room, again cowered against the wall, frightened and surly.

Jack Benson told as much of the story as he thought wise, though he felt it best to leave out the names of M. Lemaire and Mlle. Nadiboff.

Next Hal described how, at the hotel, he had set himself to watching Gaston; how he had shadowed the fellow.

"Did he come out here in an auto?" asked Jack.

"No; if he had, I couldn't have followed," Hal responded. "But this place is barely four miles from the hotel. We can get back in an hour."

"What ye goin' to do with this feller, anyway?" demanded Hickey, jerking a thumb in the direction of the frightened Gaston.

"Turn him over to the police," spoke Jack, promptly. "Even if we fail to prove anything else Hal can help me fasten a charge of felonious assault on the scoundrel. That will be enough to keep him locked up for a couple of years to come."

Gaston heard this with a falling jaw, though he did not venture to say anything.

"Well, Jerry and me are ready whenever you are, mates," hinted big Hickey.

Jack nodded, and they filed out, Jerry coming last of all to make sure that the Frenchman did not lag behind.

"Now, stand up, me bucko," ordered Hickey, seizing the chauffeur's collar as that worthy crawled through the bushes at the outer end of the tunnel. "Tryin' to steal submarine secrets, was ye? So some foreign nation'd have the trick of blowing our battleships to pieces, and the sailors on 'em? Jerry, wot d'ye reckon 'ud be about right for Frenchy!"

"Pass him over to me and I'll see," grinned the smaller sailor.

Hickey grasped the frightened chauffeur in both hands, then fairly hurled him at the smaller sailor. Jerry struck him once, with each lively fist, then sent the fellow spinning back to Hickey. The latter caught Gaston, tossing him up in the air, then striking him hard as the fellow came down. This done, the chauffeur was again hurled back at Jerry. For some time the two sailors kept this up. It was rough, heavy punishment. Gaston bellowed like a sick bull under all the strenuous handling. He must have ached in every bone in his body when Hickey finally caught him, on a rebound, and held him off at arm's length.

"Had about enough, Frenchy?" demanded the big sailor.

"Oh, mercy, monsieur!" panted the fellow wailingly. "I have had much plenty to last me all my life."

"I wish I knew whether ye was lyin'," muttered Hickey, thoughtfully. "I don't feel a bit tired, yet. Do you, Jerry?"

"Me? The exercise has warmed me up fine," grinned the smaller sailor.

"Mercy, messieurs, mercy!" wailed Gaston, sinking down to his shaking knees, for he feared that these grim tormentors meant to kill him.

"I'd just as soon you'd let up on the scoundrel, if you don't mind, mates," broke in Jack. "You see what a cur he is when he isn't having it all his own way. I told him, back in the cave, that he'd be just this sort of a fellow if the tables happened to be turned."

"Did ye say ye was going to turn him over to the officers?" asked Hickey.

"Yes," spoke Jack Benson, decisively. "A fellow plying the trade of this one needs to be locked up as long as possible."

"Oh, no, no, no, my brave Captain!" implored Gaston, wobbling around upon his knees so as to face the submarine boy. "Not the jail! Not the prison! Me! I have always been as free as the birds of the air. I would die in prison."

"I can't see where much loss will come in if you do," retorted Jack, coldly. "Hal, you brought the handcuffs out with you?"

He held up both pairs.

"No, no, no!" pleaded Gaston, almost tearfully. "Not such disgrace as that!"

"Let me have a pair of the bracelets," requested Hickey, holding out one of his hands. "Now, my tine bird, let me clip yer wings."

Gaston submitted meekly enough, then was dragged to his feet.

While Hal had brought out the lantern and the handcuffs, famished, thirst-tormented Jack Benson had looked after the water bottle and the sandwiches. Now, as all hands trudged along toward the beach the young skipper ate and drank to his full content.

Arrived in town, they roused a cottager. From him they learned where to find the police station. Gaston was thrown into a cell, and Jack entered formal complaint against the fellow.

Jacob Farnum still awake, was found at the hotel. When Hickey and Jerry returned aboard the gunboat neither felt so sorry about not having located a smuggler's camp in full operation. Jacob Farnum had taken the sailor pair apart, presenting each with a hundred-dollar bill.



CHAPTER XIV

A REMEMBRANCE FROM SHORE

It was a drowsy looking submarine party that retired to a room in the hotel to talk over the situation.

"Now, of course, first of all," declared Jacob Farnum, "we must take word of this whole affair to the commanding officer of the gunboat. As the representative, here, of the United States Government, he can give us some advice as to what to do. I am wondering whether M. Lemaire and Mlle. Nadiboff can be arrested."

"Hal," demanded Jack, turning to his chum, "when you were prowling about at the cave, did you hear Gaston mention the name of M. Lemaire?"

"No," replied Hastings, shaking his head.

"Then there wouldn't be any witness to confirm my testimony," sighed Captain Benson. "Without such a witness to aid me, I don't see how we could expect to prove anything legally against M. Lemaire."

"As for that pretty young Russian woman—" began Mr. Farnum.

"We haven't a single line of proof we could put out against her," interposed Benson. "She will have to escape, I am afraid. For that matter, I'd hate to help in the prosecution of a woman."

"So would I," retorted Mr Farnum. "Yet, if she is helping to undermine the secrets of the United States Government, something will have to be done to stop her."

"Perhaps," hinted Jack, "the best thing to do will be to see the commander of the gunboat."

"Much the better course," observed David Pollard, who, during the last few moments had seemed dreamily silent. "As you yourself suggested, Farnum, that officer should be consulted before a single step is taken in the matter."

"Then we'll all go down to the shore," decided the shipbuilder. "Even at this hour we shall find a boat."

Ten minutes later the party had clambered up on the platform deck of the "Benson." Williamson, having been left to sleep there alone through the night, had secured the entrance to the conning tower. A few sound thumps on the deck, however, roused that machinist, who, donning slippers and trousers, quickly ran up the spiral stairway, admitting them.

"I'm mighty thankful to see you back, Captain," was the machinist's greeting.

There being still nearly two hours of time to elapse before a call could well be made aboard the gunboat, Jack and Hal threw themselves into the berths of one of the staterooms. That brief, sound nap proved the saving of them when, finally, with Messrs. Farnum and Pollard, they went on board the "Waverly."

Lieutenant Commander Kimball received them in his own cabin, hearing Jack's story with utter amazement.

"What I advise you to do, gentlemen, is to go ahead and prosecute the fellow Gaston on the charge of felonious assault. I would, however, try to avoid having any testimony brought out in court to-day. I will send one of my officers to see the public prosecutor, and ask that official to have the case continued for one week. I will also wire the Navy Department at Washington, and await the reply of the Secretary before taking any other steps or offering you any other advice. But do not needlessly alarm Lemaire or the young woman away from here."

So well did the lieutenant commander accomplish his purpose that, when Jack and Hal went to the local court that forenoon, the public prosecutor promptly asked to have the case against the chauffeur continued for one week, and the court as promptly assented.

Gaston was taken back to jail. Though the fellow was well supplied with money, he did not have anywhere near enough to put up the five thousand dollars cash bail demanded by Florida justice.

At the jail a watch was kept to see whether Gaston would have visitors, but none came. M. Lemaire and Mlle. Nadiboff were known to be still at the hotel, but they did not go near their man in trouble. Neither did Lemaire or the Russian appear about the grounds of the hotel.

At noon a letter from Lieutenant Commander Kimball came aboard the submarine, inquiring whether Captain Benson could make it convenient to take him and several officers out to sea afternoon and give an exhibition of the boat's diving powers.

"After we've taken the boat out ourselves, and tested her," was the answer Captain Jack sent back. "With so many spies about we want to be sure that the boat is in safe running order before we risk the lives of half a dozen naval officers."

A luncheon was eaten, after which, the young submarine captain hastily climbed the stairs to the conning tower.

"Throw on the gasoline, Hal," he called back over his shoulder. "And, as soon as we get way, test all the electric connections, before we attempt to do any diving. Be sure of everything old fellow."

Forward in the engine room the gas motors were soon moving merrily. By the time that Eph had cast loose from moorings Jack signaled for slow speed ahead, and the grim-looking little Benson moved on out of the harbor.

Once out of the harbor Captain Jack rang, successively, for two higher speeds. The "Benson" answered both like a charm.

"The gasoline part of the craft is working all right," declared the youthful skipper to Eph, who had come up into the tower.

Fifteen minutes later Hal shouted up:

"All electric connections appear safe, Captain. And all the air compressors are working."

"Are you ready to shut off the gasoline motors?"

"Yes, sir."

"Go ahead, then, and we'll take a dive." Down they shot below the surface, the boat going on a diving keel. Then, for some minutes, Captain Jack ran his submarine pride along at a depth of fifty feet below surface.

"Might as well rise, Captain," called up Mr. Farnum, coming from his stateroom.

So Eph, at the young commander's orders, stood by to let the compressed air gradually into the water tanks. As gracefully as ever the "Benson" rose to the surface. Gasoline power was turned on again.

"Everything is all safe, Captain," nodded Mr. Farnum. "Run back and get your naval party."

As they were to run, now, on the surface, Jack stepped out to stand by the deck wheel Eph and Hal came out with him, David Pollard standing further aft.

As the submarine rounded in under the gunboat's stern the voice of Kimball called:

"As well done as ever, Mr. Benson! When shall we come on board?"

"As soon as we're moored, sir," Jack shouted

As the "Benson" ran to her moorings the youthful captain espied a shore boat that bore, as sole passenger, one of the uniformed, colored bell boys from the hotel.

When Eph made the mooring cable fast, this shore boat ranged alongside.

"Box for Captain Benson, sah," called the negro.

"Right here," acknowledged Jack, going over to the rail. The box proved to be of pasteboard.

"Are you going to open it?" whispered Farnum.

"Why, yes, sir; of course," Jack answered.

"Better do it on deck, then," came the dry answer. "It might contain something explosive, you know."

Though he laughed, young Benson carefully untied the string that held the lid on, also carefully removing the latter. Inside he discovered a handsome bouquet of roses, with a card attached.

"Well, of all the assurance in the world?" gasped Jack Benson.

"What's the matter!" queried Farnum.

"Read what's written on this card, sir."

The inscription ran:

"Mlle. Sara Nadiboff is delighted at learning that Captain Jack Benson has returned in safety from his long walk."

"Any answer, sah?" demanded the darkey in the boat.

"None, thank you," replied Captain Jack, in an even tone.

The boat continued on its way to the shore.

"Say, what do you think of that?" demanded Eph, after he, too, had taken a look at the card tied to the flowers.

"It is plain enough that our charming young Russian doesn't mean to drop Captain Benson's acquaintance just yet, if she can help it," laughed the shipbuilder.

"What are you going to do with the flowers, old man?" asked Hal.

"Flowers should be put in water, to make them keep, shouldn't they" queried the young submarine skipper, innocently.

"Yep," nodded Eph Somers.

"I hope these will keep fresh a long time, then," murmured Benson.

Raising the bouquet he dropped it overboard the harbor—on the side of the boat away from the hotel.



CHAPTER XV

CAPTAIN JACK BECOMES SUSPICIOUS

So successful and enjoyable a trip did the naval officers have that, as the "Benson" was gliding back to the harbor, Lieutenant Commander Kimball broached a subject that had begun to interest the society people among the winter visitors to Spruce Beach.

"Mr. Farnum," inquired the naval officer, "I have a favor to ask of you."

"You know in advance, Mr. Kimball, that it is granted."

"I hope it is, if it's a wise favor to ask," smiled the naval officer. "In brief, the idea is this: Naturally people in this neighborhood are all agog over this submarine craft. Some of the more daring of the ladies have besought me to arrange for a few of them to have a trip on board, even to running beneath the surface. Will you do that, for a party of our friends, to-morrow afternoon?"

"We've been a good deal beset by spies lately as you have means of knowing," replied Mr. Farnum, slowly. "You'll guarantee all of the guests, of course."

"As a naval officer I wouldn't bring anyone aboard here whom I doubted," replied the lieutenant commander, flushing.

"I didn't mean to be offensive, Mr. Kimball. But I have as great a reason as Uncle Sam can have for wanting to preserve the secrets of this boat from all but sworn officers and men of the Navy. You and I are one in that desire, Mr. Kimball, so we'll gladly take out any party, ladies included, that you bring on board."

"Thank you," answered Kimball. "And I can assure you that I shall be very careful in making up my party. Oh, but won't there be fluttering hearts at Spruce Beach tonight And I'm more than half afraid that I shall make an enemy of every lady of my acquaintance whom I have to leave out of the affair. How many, guests can you take, Mr. Farnum?"

"Not above fourteen, all told," replied the shipbuilder.

"Then I shall go ashore myself this evening, to deliver my invitations."

The shipbuilder also went ashore that evening, just to see whether he could learn anything about M. Lemaire and Mlle. Nadiboff. Almost the first person Farnum encountered was reporter Hennessy.

"Oh, your people are still here," answered Hennessy, in response to the shipbuilder's question. "They're both keeping in the background, though. It looks as though they feared to run away, and were waiting to see whether the lightning were going to strike them. Now, that I've told you so much, Mr. Farnum, can't you give me a little more of the inside of this whole strange business?"

"If I did," smiled the shipbuilder, "you'd send it to your paper."

"Of course," admitted the reporter, honestly.

"I'll tell you the best I can do, Hennessy. You keep your eyes and ears open for us, and I'll give you this news story before I give it to any other newspaper man."

"You surely will?" demanded the newspaper eagerly.

"I will."

"Then I'm here to help you"

As the lieutenant commander had predicted, the ladies at the hotels were in a flutter of excitement that evening. Every one who heard of the projected trip on the submarine boat, it seemed, wanted to be invited. By the time that Mr. Kimball's list was made up it consisted of three men and nine women, these in addition to the lieutenant commander himself and Mr Featherstone.

As Jack paced the far end of the veranda that evening a girlish figure, only poorly concealed under a light wrap, stole after him. As the young woman reached him she threw back a light veil, revealing the very pretty face of Mlle. Nadiboff.

"So, my Captain," she cried, "you would forget me when you are getting up a party to take a cruise on your wonderful craft?"

If young Benson felt anything as he looked, he was staggered by this amazing bit of effrontery.

"You do not answer me," cried Mlle. Nadiboff. "You feel guilty indeed, then?"

"Perhaps 'astonished' would be the more accurate word," Jack replied, smiling now.

"My Captain, you were very pleasant with me, the first evening that we met."

"That was before," nodded Captain Benson, still smiling. He stood cap in hand, his whole bearing respectful, for he did not intend to be discourteous even to this known adventuress. He would grant her at least the courtesy due her sex.

"Before what?" she asked.

"Well, er—before that automobile ride the day."

"And why should that change your attitude toward me, my Captain?" asked the young Russian. Her tone was coaxing, almost cooing; her eyes extremely moist, as though the tears would spring forth in another instant.

"Why, you see, Mademoiselle," laughed Jack, coolly, "the finish of that automobile ride was just a trifle too exciting for me. I have plenty of the strenuous side of life out at sea. When on shore my tastes are all for the quiet, peaceful life."

"But surely you do not reproach me with having made the automobile ride unpleasant?"

"Only that, as I remember it, you dropped some dust—or something—into my eyes, and right after that two men took me away in your car—and then things happened to me."

"Why, that was all a joke," protested the handsome young woman, gazing keenly into his eyes.

"Then I'll laugh now—ha! ha! But seriously, Mademoiselle, I haven't a sense of humor that will appreciate carrying a joke quite as far as that one was carried."

"It was all a joke," Mlle Nadiboff insisted. "At least, M. Lemaire so assured me. What ever you may have thought, my Captain, I beg you will not believe that I had any notion of helping to cause you real discomfort."

Her tone was so sincere in its ring, her eyes looked so honestly and appealingly into the boy's that Jack, for an instant, had to wonder whether he were dreaming.

"My Captain," continued the Russian girl, in a voice that trembled softly, "I see, now, that I have been fearfully—cruelly—misunderstood by you. That is more than I can bear. Come, let us take a little walk together in the grounds. I want you to tell me just what part you thought I had in some affair against you. I insist; it is my right to know this. Your arm, my Captain!"

As she spoke, Mlle. Nadiboff slipped her soft little right hand inside of Captain Jack's arm.

Captain Jack took hold of that hand to disengage it. But Mlle. Nadiboff merely held the tighter, while the boy was conscious that she was gazing up at him appealingly.

"I don't wish to be rude, Mademoiselle; don't, force me to be," the submarine boy urged. "Will you kindly release my arm?"

Then, with a subdued though angry exclamation, the girl obeyed.

"You will not even hear me?" she cried, stamping one foot lightly against the veranda boards, while now her eyes brimmed with tears.

"By jove, but she's a bully actor," thought Benson, with a sort of admiration.

"I am sorry, Mademoiselle," he replied, "But I am wanted now. I am forced to say 'good evening.'"

With a bow he turned and left her, replacing his cap as he strode away.

"Oh, that fool, that unnatural young man!" she cried, angrily, to herself. "He prefers what he calls 'duty' to the friendly glance of a pretty eye. Bah! Perhaps he is laughing at me at this moment. If he is, he is laughing much too soon, for I shall teach him a lesson or two. You are not yet beyond my reach, my brave young Captain!"

The veil that Mlle. Nadiboff carefully wound so that two folds fell across her face concealed a hard, sneering, almost barbaric look that had crept quickly into that handsome young face.

But Jack joined his own party at once. Through the rest of the evening he did not encounter either the young woman or M. Lemaire. The latter, in fact, had made himself practically invisible of late.

The next afternoon, early, a launch from the gunboat brought off the pleasure party that was to make the trip on the submarine boat.

Mr. Farnum and David Pollard were ashore at this time. Captain Jack and Eph Somers stood on the platform deck to receive and welcome the party.

The first young woman to whom Benson extended his hand to help her aboard held up a camera for him to take first of all.

"Thank you," responded the young skipper, gravely. "We will send this camera to the engine room. It will be returned to you at the end of the trip."

As he spoke, he slipped the camera box back to Eph, who started for the conning tower with it.

"But I wish to take some photographs with it," cried the young woman, indignantly. "Especially, a flashlight when we are below the surface of the ocean."

"I am most sorry, madam," Captain Jack replied, politely, "but it is wholly out of the question for any photographs to be made aboard the boat."

"No cameras! No photographs?" cried two other young women, in something like consternation. Then one of them added:

"But we want two or three photos as souvenirs—Mr. Kimball, we appeal to you."

"I am wholly powerless in the matter," replied the lieutenant commander, gravely. "Mr. Benson commands aboard this boat, and enforces the rules. I may add, however, that am wholly in sympathy with his decision. You will understand, ladies, that there are many secrets in the handling of a submarine craft like this, It would be absolutely out of the question to allow anyone to carry away photographs of the interior or the working parts of the 'Benson.'"

With that, two more cameras were passed up. Eph as quickly handed them through the conning tower to Hal, who took them down to the engine room.

Then Jack helped his visitors aboard, while Eph slipped forward to let go the moorings at the order.

"Now, ladies and gentlemen," announced Captain Jack, "I think there will be room for all on deck. If it pleases you, therefore, I propose that all remain on the platform deck while we make our run out to sea. Then, when it comes time to dive and run under the surface, we can go below."

This plan appeared to suit nearly everyone.

"But I believe I'll go below, now," proposed one tall, blond, strongly built young woman who looked somewhat Swedish. "I am afraid of too much chill air on the sea."

"Then, if it please the rest, we will all go below," Jack answered amiably.

There was instantly a chorus of dissent. The tall, blond young woman had already made her way to the conning tower, accompanied by a young man of English appearance. But Eph unconcernedly barred their way.

"Step aside, if you please, young man," urged the Englishman. "The lady wishes to go below."

"Captain's permission necessary, sir," replied Somers, quietly.

"You see, ladies and gentlemen," Jack explained, "it won't be quite possible to let visitors roam at will over the boat. It would be against my instructions from the owner. Either all must remain on deck, or all must go below."

As he spoke the young skipper thought he saw a swift look pass between the young Swedish woman and her English escort.

"Oh, well," replied the young woman, shrugging her shoulders, "I do not intend to be disagreeable. If the others wish to remain on deck, I will do so, too."

"Very good, Miss Peddensen," murmured the young Englishman.

Jack Benson took his place at the deck wheel, and Eph, after Hal had come to the conning tower opening, hurried forward once more to cast off the moorings. Then speed was called for, and the "Benson" made a graceful sight as she swept out of the little harbor with such a brilliant, interested company aboard.

The submarine continued until she was three miles out at sea.

"Now, if it pleases the company," Captain Jack called out, "we will go below and dive. Then you, will know what it feels like to be running under the surface."

From the ladies came a few little gasps of excitement. Some of them, now that the moment had come, almost wished they had remained ashore.

"No one need be afraid," smiled Jack. "This boat has been thoroughly tested. We shall go below the surface, true, but we shall come up again the instant that the proper devices are applied to our machinery. Let no one be afraid. There is not even a particle of danger."

"Not a particle," repeated Lieutenant Commander Kimball. "This is an even safer sport than automobiling."

"Let the Navy officers go below first, please," urged Jack, as the ladies began to crowd about the conning tower. He wanted this done in, order that both Mr. Kimball and Mr. Featherstone might be able to use their eyes on the guests below.

At last all had passed down the iron staircase save Eph, who remained by the wheel in the conning tower.

"Pass directly aft, everybody, please," called Jack, quietly.

"What's that for?" asked Miss Peddensen.

"We cannot allow anyone except naval officers to see how our diving apparatus is worked", replied Jack. "Some of you step into the staterooms, on either side, please. All of the visitors must be aft of this curtain."

The extreme after end of the cabin had been rigged with a heavy curtain that could be dropped into place.

"Why, I feel as if we were all being penned up here and held for the slaughter," gasped one American girl, in a tone of fright.

"Yes, indeed!" protested Miss Peddensen. "This is going too far."

"It strikes me as being a good deal like an outrage," blurted the young Englishman. "Mr. Kimball, can't you—won't you interfere in this matter?"

"I am very sorry," replied the lieutenant commander, "but I cannot. This step is necessary, in order to prevent anyone from having an improper view of the working of the craft. I am going behind the curtain with you. Mr. Featherstone will remain out in the cabin to aid in the handling of the boat. You need none of you feel any uneasiness."

Both Miss Peddensen and the Englishman ceased their objections. But Jack, remembering the glance that had passed between the pair on deck, remained behind the curtain, too, as he dropped it.

"Go ahead, Hal!" he called. "Fifty feet under the surface. Dive gently."

"O-o-o-oh!" came in little screams of alarm as the guests felt the floor on which they stood inclining at a sloping angle.

"We're going below the surface now," young Benson informed them. "We'll soon be running on an even keel."

"All below," called Hal Hastings in a few moments.

"And all clear?" asked Jack.

"All clear, Captain."

"Jack Benson threw aside the heavy curtain, come forward, slowly ladies and gentlemen, and take seats," was Jack's invitation. "I am sorry I shall have to ask you all to remain seated, but we cannot have any serious shifting of weight while we are running under the water."

Though Eph was at the tower wheel Hal Hastings was now virtually in command of the boat, by previous arrangement, for young Benson meant to keep a sharp, though covert, eye on passengers.

The young skipper noted, swiftly, that Miss Peddensen had taken the seat furthest aft in the cabin, while the young Englishman was seated at the forward end of the party of guests.

"Oh, I say, Captain Benson," called the Englishman, "are you permitted to show me how you know just how far below the surface you are?"

"The gauge tells that," replied Jack. "But I will ask you to excuse me from describing it, as I wish to keep my mind on the running of the boat. Mr. Hastings will oblige you; or, I don't doubt, one of the naval officers will."

Even this momentary distraction, however, had given Miss Peddensen time to slip something out of one of her wide sleeves into her lap. And now the young Swedish woman sat so that the object taken from her sleeve was concealed behind the woman who sat next to her.

It wasn't many moments ere Jack noted some thing about the young Swedish woman that caused the young skipper to turn, every now and then, for a swift though hidden glance in her direction.

"What on earth is Miss Peddensen doing?" wondered the submarine boy. "Hang it, I believe she's up to something that she ought not to be doing!"

Through he did not turn and walk in her direction, Jack, thereafter, kept the young Swedish woman much more under secret observation.

"By Jove, I know what she's doing, now," muttered the young skipper. "That movement of her elbow betrays her, and her eyes are fixed, much of the time on her lap. If she isn't sketching something, on the sly, then my eyesight isn't as good as it used to be!"

Captain Jack Benson found himself quickly aquiver with suspicion and indignation.

"Yet I can't afford to make any mistakes," he told himself, uneasily. "I've got to be absolutely sure before I can take the risk of starting a human cyclone about my ears!"



CHAPTER XVI

THE GOVERNMENT TAKES A HAND

Yet, for a brief interval more, Jack Benson hesitated.

"Is the young woman sketching, or is she merely writing?" he wondered, anxiously. He watched her a little while longer.

"No; she's sketching. Those are drawing strokes she's making."

Then, looking wholly blank, Jack Benson turned on his heel. He looked first at one mechanism, then at another. Yet, presently, stood close to Lieutenant Commander Kimball's ear.

Only a few words were said, but the naval officer understood instantly.

As Captain Jack turned and went back, Kimball also sauntered along, although he did not appear interested in the submarine boy's movements. Yet it was not long when both appeared before the young Swedish woman.