He stops, with laughing eyes and mocking mouth, and accompanies a "Good day, how do you do?" with a gracious gesture of salutation.

I respond coldly to his politeness—a fact which he affects not to notice.

"May Saint Jonathan protect you, Mr. Gaydon!" he continues in his clear, ringing voice. "You are not, I presume, disposed to regret the fortunate circumstance by which you were permitted to visit this surpassingly marvellous cavern—and it really is one of the finest, although the least known on this spheroid."

This word of a scientific language used in conversation with a simple hospital attendant surprises me, I admit, and I merely reply:

"I should have no reason to complain, Mr. Serko, if, after having had the pleasure of visiting this cavern, I were at liberty to quit it."

"What! Already thinking of leaving us, Mr. Gaydon,—of returning to your dismal pavilion at Healthful House? Why, you have scarcely had time to explore our magnificent domain, or to admire the incomparable beauty with which nature has endowed it."

"What I have seen suffices," I answer; "and should you perchance be talking seriously I will assure you seriously that I do not want to see any more of it."

"Come, now, Mr. Gaydon, permit me to point out that you have not yet had the opportunity of appreciating the advantages of an existence passed in such unrivalled surroundings. It is a quiet life, exempt from care, with an assured future, material conditions such as are not to be met with anywhere, an even climate and no more to fear from the tempests which desolate the coasts in this part of the Atlantic than from the cold of winter, or the heat of summer. This temperate and salubrious atmosphere is scarcely affected by changes of season. Here we have no need to apprehend the wrath of either Pluto or Neptune."

"Sir," I reply, "it is impossible that this climate can suit you, that you can appreciate living in this grotto of——"

I was on the point of pronouncing the name of Back Cup. Fortunately I restrained myself in time. What would happen if they suspected that I am aware of the name of their island, and, consequently, of its position at the extremity of the Bermuda group?

"However," I continue, "if this climate does not suit me, I have, I presume, the right to make a change."

"The right, of course."

"I understand from your remark that I shall be furnished with the means of returning to America when I want to go?"

"I have no reason for opposing your desires, Mr. Gaydon," Engineer Serko replies, "and I regard your presumption as a very natural one. Observe, however, that we live here in a noble and superb independence, that we acknowledge the authority of no foreign power, that we are subject to no outside authority, that we are the colonists of no state, either of the old or new world. This is worth consideration by whomsoever has a sense of pride and independence. Besides, what memories are evoked in a cultivated mind by these grottoes which seem to have been chiselled by the hands of the gods and in which they were wont to render their oracles by the mouth of Trophonius."

Decidedly, Engineer Serko is fond of citing mythology! Trophonius after Pluto and Neptune? Does he imagine that Warder Gaydon ever heard of Trophonius? It is clear this mocker continues to mock, and I have to exercise the greatest patience in order not to reply in the same tone.

"A moment ago," I continue shortly, "I wanted to enter yon habitation, which, if I mistake not, is that of the Count d'Artigas, but I was prevented."

"By whom, Mr. Gaydon?"

"By a man in the Count's employ."

"He probably had received strict orders about it."

"Possibly, yet whether he likes it or not, Count d'Artigas will have to see me and listen to me."

"Maybe it would be difficult, and even impossible to get him to do so," says Engineer Serko with a smile.

"Why so?"

"Because there is no such person as Count d'Artigas here."

"You are jesting, I presume; I have just seen him."

"It was not the Count d'Artigas whom you saw, Mr. Gaydon."

"Who was it then, may I ask?"

"The pirate Ker Karraje."

This name was thrown at me in a hard tone of voice, and Engineer Serko walked off before I had presence of mind enough to detain him.

The pirate Ker Karraje!

Yes, this name is a revelation to me. I know it well, and what memories it evokes! It by itself explains what has hitherto been inexplicable to me. I now know into whose hands I have fallen.

With what I already knew, with what I have learned since my arrival in Back Cup from Engineer Serko, this is what I am able to tell about the past and present of Ker Karraje:

Eight or nine years ago, the West Pacific was infested by pirates who acted with the greatest audacity. A band of criminals of various origins, composed of escaped convicts, military and naval deserters, etc., operated with incredible audacity under the orders of a redoubtable chief. The nucleus of the band had been formed by men pertaining to the scum of Europe who had been attracted to New South Wales, in Australia, by the discovery of gold there. Among these gold-diggers, were Captain Spade and Engineer Serko, two outcasts, whom a certain community of ideas and character soon bound together in close friendship.

These intelligent, well educated, resolute men would most assuredly have succeeded in any career. But being without conscience or scruples, and determined to get rich at no matter what cost, deriving from gambling and speculation what they might have earned by patient and steady work, they engaged in all sorts of impossible adventures. One day they were rich, the next day poor, like most of the questionable individuals who had hurried to the gold-fields in search of fortune.

Among the diggers in New South Wales was a man of incomparable audacity, one of those men who stick at nothing—not even at crime—and whose influence upon bad and violent natures is irresistible.

That man's name was Ker Karraje.

The origin or nationality or antecedents of this pirate were never established by the investigations ordered in regard to him. He eluded all pursuit, and his name—or at least the name he gave himself—was known all over the world, and inspired horror and terror everywhere, as being that of a legendary personage, a bogey, invisible and unseizable.

I have now reason to believe that Ker Karraje is a Malay. However, it is of little consequence, after all. What is certain is that he was with reason regarded as a formidable and dangerous villain who had many crimes, committed in distant seas, to answer for.

After spending a few years on the Australian goldfields, where he made the acquaintance of Engineer Serko and Captain Spade, Ker Karraje managed to seize a ship in the port of Melbourne, in the province of Victoria. He was joined by about thirty rascals whose number was speedily tripled. In that part of the Pacific Ocean where piracy is still carried on with great facility, and I may say, profit, the number of ships pillaged, crews massacred, and raids committed in certain western islands which the colonists were unable to defend, cannot be estimated.

Although the whereabouts of Ker Karraje's vessel, commanded by Captain Spade, was several times made known to the authorities, all attempts to capture it proved futile. The marauder would disappear among the innumerable islands of which he knew every cove and creek, and it was impossible to come across him.

He maintained a perfect reign of terror. England, France, Germany, Russia and America vainly dispatched warships in pursuit of the phantom vessel which disappeared, no one knew whither, after robberies and murders that could not be prevented or punished had been committed by her crew.

One day this series of crimes came to an end, and no more was heard of Ker Karraje. Had he abandoned the Pacific for other seas? Would this pirate break out in a fresh place? It was argued that notwithstanding what they must have spent in orgies and debauchery the pirate and his companions must still have an enormous amount of wealth hidden in some place known only to themselves, and that they were enjoying their ill-gotten gains.

Where had the band hidden themselves since they had ceased their depredations? This was a question which everybody asked and none was able to answer. All attempts to run them to earth were vain. Terror and uneasiness having ceased with the danger, Ker Karraje's exploits soon began to be forgotten, even in the West Pacific.

This is what had happened—and what will never be known unless I succeed in escaping from Back Cup:

These wretches were, as a matter of fact, possessed of great wealth when they abandoned the Southern Seas. Having destroyed their ship they dispersed in different directions after having arranged to meet on the American continent.

Engineer Serko, who was well versed in his profession, and was a clever mechanic to boot, and who had made a special study of submarine craft, proposed to Ker Karraje that they should construct one of these boats in order to continue their criminal exploits with greater secrecy and effectiveness.

Ker Karraje at once saw the practical nature of the proposition, and as they had no lack of money the idea was soon carried out.

While the so-called Count d'Artigas ordered the construction of the schooner Ebba at the shipyards of Gotteborg, in Sweden, he gave to the Cramps of Philadelphia, in America, the plans of a submarine boat whose construction excited no suspicion. Besides, as will be seen, it soon disappeared and was never heard of again.

The boat was constructed from a model and under the personal supervision of Engineer Serko, and fitted with all the known appliances of nautical science. The screw was worked with electric piles of recent invention which imparted enormous propulsive power to the motor.

It goes without saying that no one imagined that Count d'Artigas was none other than Ker Karraje, the former pirate of the Pacific, and that Engineer Serko was the most formidable and resolute of his accomplices. The former was regarded as a foreigner of noble birth and great fortune, who for several months had been frequenting the ports of the United States, the Ebba having been launched long before the tug was ready.

Work upon the latter occupied fully eighteen months, and when the boat was finished it excited the admiration of all those interested in these engines of submarine navigation. By its external form, its interior arrangements, its air-supply system, the rapidity with which it could be immersed, the facility with which it could be handled and controlled, and its extraordinary speed, it was conceded to be far superior to the Goubet, the Gymnote, the Zede, and other similar boats which had made great strides towards perfection.

After several extremely successful experiments a public test was given in the open sea, four miles off Charleston, in presence of several American and foreign warships, merchant vessels, and pleasure boats invited for the occasion.

Of course the Ebba was among them, with the Count d'Artigas, Engineer Serko, and Captain Spade on board, and the old crew as well, save half a dozen men who manned the submarine machine, which was worked by a mechanical engineer named Gibson, a bold and very clever Englishman.

The programme of this definite experiment comprised various evolutions on the surface of the water, which were to be followed by an immersion to last several hours, the boat being ordered not to rise again until a certain buoy stationed many miles out at sea had been attained.

At the appointed time the lid was closed and the boat at first manoeuvred on the surface. Her speed and the ease with which she turned and twisted were loudly praised by all the technical spectators.

Then at a signal given on board the Ebba the tug sank slowly out of sight, and several vessels started for the buoy where she was to reappear.

Three hours went by, but there was no sign of the boat.

No one could suppose that in accordance with instructions received from the Count d'Artigas and Engineer Serko this submarine machine, which was destined to act as the invisible tug of the schooner, would not emerge till it had gone several miles beyond the rendezvous. Therefore, with the exception of those who were in the secret, no one entertained any doubt that the boat and all inside her had perished as the result of an accident either to her metallic covering or machinery.

On board the Ebba consternation was admirably simulated. On board the other vessels it was real. Drags were used and divers sent down along the course the boat was supposed to have taken, but it could not be found, and it was agreed that it had been swallowed up in the depths of the Atlantic.

Two days later the Count d'Artigas put to sea again, and in forty-eight hours came up with the tug at the place appointed.

This is how Ker Karraje became possessed of the admirable vessel which was to perform the double function of towing the schooner and attacking ships. With this terrible engine of destruction, whose very existence was ignored, the Count d'Artigas was able to recommence his career of piracy with security and impunity.

These details I have learned from Engineer Serko, who is very proud of his handiwork,—and also very positive that the prisoner of Back Cup will never be able to disclose the secret.

It will easily be realized how powerful was the offensive weapon Ker Karraje now possessed. During the night the tug would rush at a merchant vessel, and bore a hole in her with its powerful ram. At the same time the schooner which could not possibly have excited any suspicion, would run alongside and her horde of cutthroats would pour on to the doomed vessel's deck and massacre the helpless crew, after which they would hurriedly transfer that part of the cargo that was worth taking to the Ebba. Thus it happened that ship after ship was added to the long list of those that never reached port and were classed as having gone down with all on board.

For a year after the odious comedy in the bay of Charleston Ker Karraje operated in the Atlantic, and his wealth increased to enormous proportions. The merchandise for which he had no use was disposed of in distant markets in exchange for gold and silver. But what was sadly needed was a place where the profits could be safely hidden pending the time when they were to be finally divided.

Chance came to their aid. While exploring the bottom of the sea in the neighborhood of the Bermudas, Engineer Serko and Driver Gibson discovered at the base of Back Cup island the tunnel which led to the interior of the mountain. Would it have been possible for Ker Karraje to have found a more admirable refuge than this, absolutely safe as it was from any possible chance of discovery? Thus it came to pass that one of the islands of the Archipelago of Bermuda, erstwhile the haunt of buccaneers, became the lair of another gang a good deal more to be dreaded.

This retreat having been definitely adopted, Count d'Artigas and his companions set about getting their place in order. Engineer Serko installed an electric power house, without having recourse to machines whose construction abroad might have aroused suspicion, simply employing piles that could be easily mounted and required but metal plates and chemical substances that the Ebba procured during her visits to the American coast.

What happened on the night of the 19th inst. can easily be divined. If the three-masted merchantman which lay becalmed was not visible at break of day it was because she had been scuttled by the tug, boarded by the cut-throat band on the Ebba, and sunk with all on board after being pillaged. The bales and things that I had seen on the schooner were a part of her cargo, and all unknown to me the gallant ship was lying at the bottom of the broad Atlantic!

How will this adventure end? Shall I ever be able to escape from Back Cup, denounce the false Count d'Artigas and rid the seas of Ker Karraje's pirates?

And if Ker Karraje is terrible as it is, how much more so will he become if he ever obtains possession of Roch's fulgurator! His power will be increased a hundred-fold? If he were able to employ this new engine of destruction no merchantman could resist him, no warship escape total destruction.

I remain for some time absorbed and oppressed by the reflections with which the revelation of Ker Karraje's name inspires me. All that I have ever heard about this famous pirate recurs to me—his existence when he skimmed the Southern Seas, the useless expeditions organized by the maritime powers to hunt him down. The unaccountable loss of so many vessels in the Atlantic during the past few years is attributable to him. He had merely changed the scene of his exploits. It was supposed that he had been got rid of, whereas he is continuing his piratical practices in the most frequented ocean on the globe, by means of the tug which is believed to be lying at the bottom of Charleston Bay.

"Now," I say to myself, "I know his real name and that of his lair—Ker Karraje and Back Cup;" and I surmise that if Engineer Serko has let me into the secret he must have been authorized to do so. Am I not meant to understand from this that I must give up all hope of ever recovering my liberty?

Engineer Serko had manifestly remarked the impression created upon me by this revelation. I remember that on leaving me he went towards Ker Karraje's habitation, no doubt with the intention of apprising him of what had passed.

After a rather long walk around the lagoon I am about to return to my cell, when I hear footsteps behind me. I turn and find myself face to face with the Count d'Artigas, who is accompanied by Captain Spade. He glances at me sharply, and in a burst of irritation that I cannot suppress, I exclaim:

"You are keeping me here, sir, against all right. If it was to wait upon Thomas Roch that you carried me off from Healthful House, I refuse to attend to him, and insist upon being sent back."

The pirate chief makes a gesture, but does not reply.

Then my temper gets the better of me altogether.

"Answer me, Count d'Artigas—or rather, for I know who you are—answer me, Ker Karraje!" I shout.

"The Count d'Artigas is Ker Karraje," he coolly replies, "just as Warder Gaydon is Engineer Simon Hart; and Ker Karraje will never restore to liberty Engineer Simon Hart, who knows his secrets."



CHAPTER XI.

FIVE WEEKS IN BACK CUP.

The situation is plain. Ker Karraje knows who I am. He knew who I was when he kidnapped Thomas Roch and his attendant.

How did this man manage to find out what I was able to keep from the staff of Healthful House? How comes it that he knew that a French engineer was performing the duties of attendant to Thomas Roch? I do not know how he discovered it, but the fact remains that he did.

Evidently he had means of information which must have been costly, but from which he has derived considerable profit. Besides, men of his kidney do not count the cost when they wish to attain an end they have in view.

Henceforward Ker Karraje, or rather Engineer Serko, will replace me as attendant upon Thomas Roch. Will he succeed better than I did? God grant that he may not, that the civilized world may be spared such a misfortune!

I did not reply to Ker Karraje's Parthian shot, for I was stricken dumb. I did not, however, collapse, as the alleged Count d'Artigas perhaps expected I would.

No! I looked him straight in the eyes, which glittered angrily, and crossed my arms defiantly, as he had done. And yet he held my life in his hands! At a sign a bullet would have laid me dead at his feet. Then my body, cast into the lagoon, would have been borne out to sea through the tunnel and there would have been an end of me.

After this scene I am left at liberty, just as before. No measure is taken against me, I can walk among the pillars to the very end of the cavern, which—it is only too clear—possesses no other issue except the tunnel.

When I return to my cell, at the extremity of the Beehive, a prey to a thousand thoughts suggested by my situation, I say to myself:

"If Ker Karraje knows I am Simon Hart, the engineer, he must at any rate never know that I am aware of the position of Back Cup Island."

As to the plan of confiding Thomas Roch to my care, I do not think he ever seriously entertained it, seeing that my identity had been revealed to him. I regret this, inasmuch as the inventor will indubitably be the object of pressing solicitations, and as Engineer Serko will employ every means in his power to obtain the composition of the explosive and deflagrator, of which he will make such detestable use during future piratical exploits. Yes, it would have been far better if I could have remained Thomas Roch's keeper here, as in Healthful House.

For fifteen days I see nothing of my late charge. No one, I repeat, has placed any obstacles in the way of my daily peregrinations. I have no need to occupy myself about the material part of my existence. My meals are brought to me regularly, direct from the kitchen of the Count d'Artigas—I cannot accustom myself to calling him by any other name. The food leaves nothing to be desired, thanks to the provisions that the Ebba brings on her return from each voyage.

It is very fortunate, too, that I have been supplied with all the writing materials I require, for during my long hours of idleness I have been able to jot down in my notebook the slightest incidents that have occurred since I was abducted from Healthful House, and to keep a diary day by day. As long as I am permitted to use a pen I shall continue my notes. Mayhap some day, they will help to clear up the mysteries of Back Cup.

From July 5 to July 25.—A fortnight has passed, and all my attempts to get near Thomas Roch have been frustrated. Orders have evidently been given to keep him away from my influence, inefficacious though the latter has hitherto been. My only hope is that the Count d'Artigas, Engineer Serko, and Captain Spade will waste their time trying to get at the inventor's secrets.

Three or four times to my knowledge, at least, Thomas Roch and Engineer Serko have walked together around the lagoon. As far as I have been able to judge, the former listened with some attention to what the other was saying to him. Serko has conducted him over the whole cavern, shown him the electric power house and the mechanism of the tug. Thomas Roch's mental condition has visibly improved since his departure from Healthful House.

Thomas Roch lives in a private room in Ker Karraje's "mansion." I have no doubt that he is daily sounded in regard to his discoveries, especially by Engineer Serko. Will he be able to resist the temptation if they offer him the exorbitant price that he demands? Has he any idea of the value of money? These wretches may dazzle him with the gold that they have accumulated by years of rapine. In the present state of his mind may he not be induced to disclose the composition of his fulgurator? They would then only have to fetch the necessary substances and Thomas Roch would have plenty of time in Back Cup to devote to his chemical combinations. As to the war-engines themselves nothing would be easier than to have them made in sections in different parts of the American continent. My hair stands on end when I think what they could and would do with them if once they gained possession of them.

These intolerable apprehensions no longer leave me a minute's peace; they are wearing me out and my health is suffering in consequence. Although the air in the interior of Back Cup is pure, I become subject to attacks of suffocation, and I feel as though my prison walls were falling upon me and crushing me under their weight. I am, besides, oppressed by the feeling that I am cut off from the world, as effectually as though I were no longer upon our planet,—for I know nothing of what is going on outside.

Ah! if it were only possible to escape through that submarine tunnel, or through the hole in the dome and slide to the base of the mountain!

On the morning of the 25th I at last encounter Thomas Roch. He is alone on the other side of the lagoon, and I wonder, inasmuch as I have not seen them since the previous day, whether Ker Karraje, Engineer Serko, and Captain Spade have not gone off on some expedition.

I walk round towards Thomas Roch, and before he can see me I examine him attentively.

His serious, thoughtful physiognomy is no longer that of a madman. He walks slowly, with his eyes bent on the ground, and under his arm a drawing-board upon which is stretched a sheet of paper covered with designs.

Suddenly he raises his head, advances a step and recognizes me.

"Ah! Gaydon, it is you, is it?" he cries, "I have then escaped from you! I am free!"

He can, indeed, regard himself as being free—a good deal more at liberty in Back Cup than he was in Healthful House. But maybe my presence evokes unpleasant memories, and will bring on another fit, for he continues with extraordinary animation:

"Yes, I know you, Gaydon.—Do not approach me! Stand off! stand off! You would like to get me back in your clutches, incarcerate me again in your dungeon! Never! I have friends here who will protect me. They are powerful, they are rich. The Count d'Artigas is my backer and Engineer Serko is my partner. We are going to exploit my invention! We are going to make my fulgurator! Hence! Get you gone!"

Thomas Roch is in a perfect fury. He raises his voice, agitates his arms, and finally pulls from his pockets many rolls of dollar bills and banknotes, and handfuls of English, French, American and German gold coins, which slip through his fingers and roll about the cavern.

How could he get all this money except from Ker Karraje, and as the price of his secret? The noise he makes attracts a number of men to the scene. They watch us for a moment, then seize Thomas Roch and drag him away. As soon as I am out of his sight he ceases-to struggle and becomes calm again.

July 27.—Two hours after meeting with Thomas Roch, I went down to the lagoon and walked out to the edge of the stone jetty.

The tug is not moored in its accustomed place, nor can I see it anywhere about the lake. Ker Karraje and Engineer Serko had not gone yesterday, as I supposed, for I saw them in the evening.

To-day, however, I have reason to believe that they really have gone away in the tug with Captain Spade and the crew of the Ebba, and that the latter must be sailing away.

Have they set out on a piracy expedition? Very likely. It is equally likely that Ker Karraje, become once more the Count d'Artigas, travelling for pleasure on board his yacht, intends to put into some port on the American coast to procure the substances necessary to the preparation of Roch's fulgurator.

Ah! if it had only been possible for me to hide in the tug, to slip into the Ebba's hold, and stow myself away there until the schooner arrived in port! Then perchance I might have escaped and delivered the world from this band of pirates.

It will be seen how tenaciously I cling to the thought of escape—of fleeing—fleeing at any cost from this lair. But flight is impossible, except through the tunnel, by means of a submarine boat. Is it not folly to think of such a thing? Sheer folly, and yet what other way is there of getting out of Back Cup?

While I give myself up to these reflections the water of the lagoon opens a few yards from me and the tug appears. The lid is raised and Gibson, the engineer, and the men issue on to the platform. Other men come up and catch the line that is thrown to them. They haul upon it, and the tug is soon moored in its accustomed place.

This time, therefore, at any rate, the schooner is not being towed, and the tug merely went out to put Ker Karraje and his companions aboard the Ebba.

This only confirms my impression that the sole object of their trip is to reach an American port where the Count d'Artigas can procure the materials for making the explosive, and order the machines in some foundry. On the day fixed for their return the tug will go out through the tunnel again to meet the schooner and Ker Karraje will return to Back Cup.

Decidedly, this evildoer is carrying out his designs and has succeeded sooner than I thought would be possible.

August 3.—An incident occurred to-day of which the lagoon was the theatre—a very curious incident that must be exceedingly rare.

Towards three o'clock in the afternoon there was a prodigious bubbling in the water, which ceased for a minute or two and then recommenced in the centre of the lagoon.

About fifteen pirates, whose attention had been attracted by this unaccountable phenomenon, hurried down to the bank manifesting signs of astonishment not unmingled with fear—at least I thought so.

The agitation of the water was not caused by the tug, as the latter was lying alongside the jetty, and the idea that some other submarine boat had found its way through the tunnel was highly improbable.

Almost at the same instant cries were heard on the opposite bank. The newcomers shouted something in a hoarse voice to the men on the side where I was standing, and these immediately rushed off towards the Beehive.

I conjectured that they had caught sight of some sea-monster that had found its way in, and was floundering in the lagoon, and that they had rushed off to fetch arms and harpoons to try and capture it.

I was right, for they speedily returned with the latter weapons and rifles loaded with explosive bullets.

The monster in question was a whale, of the species that is common enough in Bermudan waters, which after swimming through the tunnel was plunging about in the narrow limits of the lake. As it was constrained to take refuge in Back Cup I concluded that it must have been hard pressed by whalers.

Some minutes elapsed before the monster rose to the surface. Then the green shiny mass appeared spouting furiously and darting to and fro as though fighting with some formidable enemy.

"If it was driven in here by whalers," I said to myself, "there must be a vessel in proximity to Back Cup—peradventure within a stone's throw of it. Her boats must have entered the western passes to the very foot of the mountain. And to think I am unable to communicate with them! But even if I could, I fail to see how I could go to them through these massive walls."

I soon found, however, that it was not fishers, but sharks that had driven the whale through the tunnel, and which infest these waters in great numbers. I could see them plainly as they darted about, turning upon their backs and displaying their enormous mouths which were bristling with their cruel teeth. There were five or six of the monsters, and they attacked the whale with great viciousness. The latter's only means of defence was its tail, with which it lashed at them with terrific force and rapidity. But the whale had received several wounds and the water was tinged with its life-blood; for plunge and lash as it would, it could not escape the bites of its enemies.

However, the voracious sharks were not permitted to vanquish their prey, for man, far more powerful with his instruments of death, was about to take a hand and snatch it from them. Gathered around the lagoon were the companions of Ker Karraje, every whit as ferocious as the sharks themselves, and well deserving the same name, for what else are they?

Standing amid a group, at the extremity of the jetty, and armed with a harpoon, was the big Malay who had prevented me from entering Ker Karraje's house. When the whale got within shot, he hurled the harpoon with great force and skill, and it sank into the leviathan's flesh just under the left fin. The whale plunged immediately, followed by the relentless sharks. The rope attached to the weapon ran out for about sixty yards, and then slackened. The men at once began to haul on it, and the monster rose to the surface again near the end of the tunnel, struggling desperately in its death agony, and spurting great columns of water tinged with blood. One blow of its tail struck a shark, and hurled it clean out of water against the rocky side, where it dropped in again, badly, if not fatally injured.

The harpoon was torn from the flesh by the jerk, and the whale went under. It came up again for the last time, and lashed the water so that it washed up from the tunnel end, disclosing the top of the orifice.

Then the sharks again rushed on their prey, but were scared off by a hail of the explosive bullets. Two men then jumped into a boat and attached a line to the dead monster. The latter was hauled into the jetty, and the Malays started to cut it up with a dexterity that showed they were no novices at the work.

No more sharks were to be seen, but I concluded that it would be as well to refrain from taking a bath in the lagoon for some days to come.

I now know exactly where the entrance to the tunnel is situated. The orifice on this side is only ten feet below the edge of the western bank. But of what use is this knowledge to me?

August 7.—Twelve days have elapsed since the Count d'Artigas, Engineer Serko, and Captain Spade put to sea. There is nothing to indicate that their return is expected, though the tug is always kept in readiness for immediate departure by Gibson, the engine-driver. If the Ebba is not afraid to enter the ports of the United States by day, I rather fancy she prefers to enter the rocky channel of Back Cup at nightfall. I also fancy, somehow, that Ker Karraje and his companions will return to-night.

August 10.—At ten o'clock last night, as I anticipated, the tug went under and out, just in time to meet the Ebba and tow her through the channel to her creek, after which she returned with Ker Karraje and the others.

When I look out this morning, I see Thomas Roch and Engineer Serko walking down to the lagoon, and talking. What they are talking about I can easily guess. I go forward and take a good look at my ex-patient. He is asking questions of Engineer Serko With great animation. His eyes gleam, his face is flushed, and he is all eagerness to reach the jetty. Engineer Serko can hardly keep up with him.

The crew of the tug are unloading her, and they have just brought ashore ten medium-sized boxes. These boxes bear a peculiar red mark, which Thomas Roch examines closely.

Engineer Serko orders the men to transport them to the storehouses on the left bank, and the boxes are forthwith loaded on a boat and rowed over.

In my opinion, these boxes contain the substances by the combination or mixture of which, the fulgurator and deflagrator are to be made. The engines, doubtless, are being made in an American foundry, and when they are ready, the schooner will fetch them and bring them to Back Cup.

For once in a while, anyhow, the Ebba has not returned with any stolen merchandise. She went out and has returned with a clear bill. But with what terrible power Ker Karraje will be armed for both offensive and defensive operations at sea! If Thomas Roch is to be credited, this fulgurator could shatter the terrestrial spheroid at one blow. And who knows but what one day, he will try the experiment?



CHAPTER XII.

ENGINEER SERKO'S ADVICE.

Thomas Roch has started work and spends hours and hours in a wooden shed on the left bank of the lagoon that has been set apart as his laboratory and workshop. No one enters it except himself. Does he insist upon preparing the explosive in secret and does he intend to keep the formula thereof to himself? I should not wonder.

The manner of employing Roch's fulgurator is, I believe, very simple indeed. The projectile in which it is used requires neither gun nor mortar to launch it, nor pneumatic tube like the Zalinski shell. It is autopropulsive, it projects itself, and no ship within a certain zone when the engine explodes could escape utter destruction. With such a weapon as this at his command Ker Karraje would be invincible.

From August 11 to August 17.—During the past week Thomas Roch has been working without intermission. Every morning the inventor goes to his laboratory and does not issue therefrom till night. I have made no attempt to stop him or speak to him, knowing that it would be useless to do so.

Although he is still indifferent to everything that does not touch upon his work he appears to be perfectly self-possessed. Why should he not have recovered his reason? Has he not obtained what he has so long sought for? Is he not at last able to carry out the plans he formed years and years ago?

August 18.—At one o'clock this morning I was roused by several detonations.

"Has Back Cup been attacked?" was my first thought. "Has the schooner excited suspicion, and been chased to the entrance to the passes? Is the island being bombarded with a view to its destruction? Has justice at last overtaken these evil-doers ere Thomas Roch has been able to complete the manufacture of his explosive, and before the autopropulsive engine could be fetched from the continent?"

The detonations, which are very violent, continue, succeeding each other at regular intervals, and it occurs to me that if the schooner has been destroyed, all communication with the bases of supply being impossible, Back Cup cannot be provisioned.

It is true the tug would be able to land the Count d'Artigas somewhere on the American coast where, money being no object, he could easily buy or order another vessel. But no matter. If Back Cup is only destroyed before Ker Karraje has Roch's fulgurator at his disposal I shall render thanks to heaven.

A few hours later, at the usual time, I quit my cell. All is quiet at the Beehive. The men are going about their business as usual. The tug is moored near the jetty. Thomas Roch is going to his laboratory, and Ker Karraje and Engineer Serko are tranquilly pacing backwards and forwards by the lake and chatting. The island therefore could not have been attacked during the night. Yet I was awakened by the report of cannon, this I will swear.

At this moment Ker Karraje goes off towards his abode and Engineer Serko, smilingly ironical, as usual, advances to meet me.

"Well, Mr. Simon Hart," he says, "are you getting accustomed to your tranquil existence? Do you appreciate at their just merit the advantages of this enchanted grotto? Have you given up all hope of recovering your liberty some day or other?"

What is the use of waxing wroth with this jester? I reply calmly:

"No, sir. I have not given up hope, and I still expect that I shall be released."

"What! Mr. Hart, separate ourselves from a man whom we all esteem—and I from a colleague who perhaps, in the course of Thomas Roch's fits of delirium, has learned some of his secrets? You are not serious!"

So this is why they are keeping me a prisoner in Back Cup! They suppose that I am in part familiar with Koch's invention, and they hope to force me to tell what I know if Thomas Koch refuses to give up his secret. This is the reason why I was kidnapped with him, and why I have not been accommodated with an involuntary plunge in the lagoon with a stone fastened to my neck. I see it all now, and it is just as well to know it.

"Very serious," I affirm, in response to the last remark of my interlocutor.

"Well," he continues, "if I had the honor to be Simon Hart, the engineer, I should reason as follows: 'Given, on the one hand, the personality of Ker Karraje, the reasons which incited him to select such a mysterious retreat as this cavern, the necessity of the said cavern being kept from any attempt to discover it, not only in the interest of the Count d'Artigas, but in that of his companions—'"

"Of his accomplices, if you please."

"'Of his accomplices,' then—'and on the other hand, given the fact that I know the real name of the Count d'Artigas and in what mysterious safe he keeps his riches—'"

"Riches stolen, and stained with blood, Mr. Serko."

"'Riches stolen and stained with blood,' if you like—'I ought to understand that this question of liberty cannot be settled in accordance with my desires.'"

It is useless to argue the point under these conditions, and I switch the conversation on to another line.

"May I ask," I continue, "how you came to find out that Gaydon, the warder, was Simon Hart, the engineer?"

"I see no reason for keeping you in ignorance on the subject, my dear colleague. It was largely by hazard. We had certain relations with the manufactory in New Jersey with which you were connected, and which you quitted suddenly one day under somewhat singular circumstances. Well, during a visit I made to Healthful House some months before the Count d'Artigas went there, I saw and recognized you."

"You?"

"My very self, and from that moment I promised myself the pleasure of having you for a fellow-passenger on board the Ebba."

I do not recall ever having seen this Serko at Healthful House, but what he says is very likely true.

"I hope your whim of having me for a companion will cost you dear, some day or other," I say to myself.

Then, abruptly, I go on:

"If I am not mistaken, you have succeeded in inducing Thomas Roch to disclose the secret of his fulgurator?"

"Yes, Mr. Hart. We paid millions for it. But millions, you know, are nothing to us. We have only the trouble of taking them! Therefore we filled all his pockets—covered him with millions!"

"Of what use are these millions to him if he is not allowed to enjoy them outside?"

"That, Mr. Hart, is a matter that does not trouble him a little bit! This man of genius thinks nothing of the future: he lives but in the present. While engines are being constructed from his plans over yonder in America, he is preparing his explosive with chemical substances with which he has been abundantly supplied. He! he! What an invention it is, this autopropulsive engine, which flies through the air of its own power and accelerates its speed till the goal is reached, thanks to the properties of a certain powder of progressive combustion! Here we have an invention that will bring about a radical change in the art of war."

"Defensive war, Mr. Serko."

"And offensive war, Mr. Hart."

"Naturally," I answer.

Then pumping him still more closely, I go on:

"So, what no one else has been able to obtain from Thomas Roch—"

"We obtained without much difficulty."

"By paying him."

"By paying him an incredible price—and, moreover, by causing to vibrate what in him is a very sensitive chord."

"What chord?"

"That of vengeance!"

"Vengeance?—against whom?"

"Against all those who have made themselves his enemies by discouraging him, by spurning him, expelling him, by constraining him to go a-begging from country to country with an invention of incontestable superiority! Now all notion of patriotism is extinct in his soul. He has now but one thought, one ferocious desire: to avenge himself upon those who have denied him—and even upon all mankind! Really, Mr. Hart, your governments of Europe and America committed a stupendous blunder in refusing to pay Roch the price his fulgurator is worth!"

And Engineer Serko describes enthusiastically the various advantages of the new explosive which, he says, is incontestably superior to any yet invented.

"And what a destructive effect it has," he adds. "It is analogous to that of the Zalinski shell, but is a hundred times more powerful, and requires no machine for firing it, as it flies through the air on its own wings, so to speak."

I listen in the hope that Engineer Serko will give away a part of the secret, but in vain. He is careful not to say more than he wants to.

"Has Thomas Roch," I ask, "made you acquainted with the composition of his explosive?"

"Yes, Mr. Hart—if it is all the same to you—and we shall shortly have considerable quantities of it stored in a safe place."

"But will there not be a great and ever-impending danger in accumulating large quantities of it? If an accident were to happen it would be all up with the island of——!"

Once more the name of Back Cup was on the point of escaping me. They might consider me too well-informed if they were aware that in addition to being acquainted with the Count d'Artigas' real name I also know where his stronghold is situated.

Luckily Engineer Serko has not remarked my reticence, and he replies:

"There will be no cause for alarm. Thomas Roch's explosive will not burn unless subjected to a special deflagrator. Neither fire nor shock will explode it."

"And has Thomas Roch also sold you the secret of his deflagrator?"

"Not yet, Mr. Hart, but it will not be long before the bargain is concluded. Therefore, I repeat, no danger is to be apprehended, and you need not keep awake of nights on that account. A thousand devils, sir! We have no desire to be blown up with our cavern and treasures! A few more years of good business and we shall divide the profits, which will be large enough to enable each one of us to live as he thinks proper and enjoy life to the top of his bent—after the dissolution of the firm of Ker Karraje and Co. I may add that though there is no danger of an explosion, we have everything to fear from a denunciation—which you are in the position to make, Mr. Hart. Therefore, if you take my advice, you will, like a sensible man, resign yourself to the inevitable until the disbanding of the company. We shall then see what in the interest of our security is best to be done with you!"

It will be admitted that these words are not exactly calculated to reassure me. However, a lot of things may happen ere then. I have learned one good thing from this conversation, and that is that if Thomas Roch has sold his explosive to Ker Karraje and Co., he has at any rate, kept the secret of his deflagrator, without which the explosive is of no more value than the dust of the highway.

But before terminating the interview I think I ought to make a very natural observation to Mr. Serko.

"Sir," I say, "you are now acquainted with the composition of Thomas Roch's explosive. Does it really possess the destructive power that the inventor attributes to it? Has it ever been tried? May you not have purchased a composition as inert as a pinch of snuff?"

"You are doubtless better informed upon this point than you pretend, Mr. Hart. Nevertheless, I thank you for the interest you manifest in our affairs, and am able to reassure you. The other night we made a series of decisive experiments. With only a few grains of this substance great blocks of rock were reduced to impalpable dust!"

This explanation evidently applies to the detonation I heard.

"Thus, my dear colleague," continues Engineer Serko, "I can assure you that our expectations have been answered. The effects of the explosive surpass anything that could have been imagined. A few thousand tons of it would burst our spheroid and scatter the fragments into space. You can be absolutely certain that it is capable of destroying no matter what vessel at a distance considerably greater than that attained by present projectiles and within a zone of at least a mile. The weak point in the invention is that rather too much time has to be expended in regulating the firing."

Engineer Serko stops short, as though reluctant to give any further information, but finally adds:

"Therefore, I end as I began, Mr. Hart. Resign yourself to the inevitable. Accept your new existence without reserve. Give yourself up to the tranquil delights of this subterranean life. If one is in good health, one preserves it; if one has lost one's health, one recovers it here. That is what is happening to your fellow countryman. Yes, the best thing you can do is to resign yourself to your lot."

Thereupon this giver of good advice leaves me, after saluting me with a friendly gesture, like a man whose good intentions merit appreciation. But what irony there is in his words, in his glance, in his attitude. Shall I ever be able to get even with him?

I now know that at any rate it is not easy to regulate the aim of Roch's auto-propulsive engine. It is probable that it always bursts at the same distance, and that beyond the zone in which the effects of the fulgurator are so terrible, and once it has been passed, a ship is safe from its effects. If I could only inform the world of this vital fact!

August 20.—For two days no incident worth recording has occurred. I have explored Back Cup to its extreme limits. At night when the long perspective of arched columns are illuminated by the electric lamps, I am almost religiously impressed when I gaze upon the natural wonders of this cavern, which has become my prison. I have never given up hope of finding somewhere in the walls a fissure of some kind of which the pirates are ignorant and through which I could make my escape. It is true that once outside I should have to wait till a passing ship hove in sight. My evasion would speedily be known at the Beehive, and I should soon be recaptured, unless—a happy thought strikes me—unless I could get at the Ebba's boat that was drawn up high and dry on the little sandy beach in the creek. In this I might be able to make my way to St. George or Hamilton.

This evening—it was about nine o'clock—I stretched myself on a bed of sand at the foot of one of the columns, about one hundred yards to the east of the lagoon. Shortly afterwards I heard footsteps, then voices. Hiding myself as best I could behind the rocky base of the pillar, I listened with all my ears.

I recognized the voices as those of Ker Karraje and Engineer Serko. The two men stopped close to where I was lying, and continued their conversation in English—which is the language generally used in Back Cup. I was therefore able to understand all that they said.

They were talking about Thomas Roch, or rather his fulgurator.

"In a week's time," said Ker Karraje, "I shall put to sea in the Ebba, and fetch the sections of the engines that are being cast in that Virginian foundry."

"And when they are here," observed Engineer Serko, "I will piece them together and fix up the frames for firing them. But beforehand, there is a job to be done which it seems to me is indispensable."

"What is that?"

"To cut a tunnel through the wall of the cavern."

"Through the wall of the cavern?"

"Oh! nothing but a narrow passage through which only one man at a time could squeeze, a hole easy enough to block, and the outside end of which would be hidden among the rocks."

"Of what use could it be to us, Serko?"

"I have often thought about the utility of having some other way of getting out besides the submarine tunnel. We never know what the future may have in store for us."

"But the walls are so thick and hard," objected Ker Karraje.

"Oh, with a few grains of Roch's explosive I undertake to reduce the rock to such fine powder that we shall be able to blow it away with our breath," Serko replied.

It can easily be imagined with what interest and eagerness I listened to this. Here was a ray of hope. It. was proposed to open up communication with the outside by a tunnel in the wall, and this held out the possibility of escape.

As this thought flashed through my mind, Ker Karraje said:

"Very well, Serko, and if it becomes necessary some day to defend Back Cup and prevent any ship from approaching it——. It is true," he went on, without finishing the reflection, "our retreat would have to have been discovered by accident—or by denunciation."

"We have nothing to fear either from accident or denunciation," affirmed Serko.

"By one of our band, no, of course not, but by Simon Hart, perhaps."

"Hart!" exclaimed Serko. "He would have to escape first and no one can escape from Back Cup. I am, by the bye, interested in this Hart. He is a colleague, after all, and I have always suspected that he knows more about Roch's invention than he pretends. I will get round him so that we shall soon be discussing physics, mechanics, and matters ballistic like a couple of friends."

"No matter," replied the generous and sensible Count d'Artigas, "when we are in full possession of the secret we had better get rid of the fellow."

"We have plenty of time to do that, Ker Karraje."

"If God permits you to, you wretches," I muttered to myself, while my heart thumped against my ribs.

And yet, without the intervention of Providence, what hope is there for me?

The conversation then took another direction.

"Now that we know the composition of the explosive, Serko," said Ker Karraje, "we must, at all cost, get that of the deflagrator from Thomas Roch."

"Yes," replied Engineer Serko, "that is what I am trying to do. Unfortunately, however, Roch positively refuses to discuss it. Still he has already made a few drops of it with which those experiments were made, and he will furnish as with some more to blow a hole through the wall."

"But what about our expeditions at sea?" queried Ker Karraje.

"Patience! We shall end by getting Roch's thunderbolts entirely in our own hand, and then——"

"Are you sure, Serko?"

"Quite sure,—by paying the price, Ker Karraje."

The conversation dropped at this point, and they strolled off without having seen me—very luckily for me, I guess. If Engineer Serko spoke up somewhat in defence of a colleague, Ker Karraje is apparently animated with much less benevolent sentiments in regard to me. On the least suspicion they would throw me into the lake, and if I ever got through the tunnel, it would only be as a corpse carried out by the ebbing tide.

August 21.—Engineer Serko has been prospecting with a view to piercing the proposed passage through the wall, in such a way that its existence will never be dreamed of outside. After a minute examination he decided to tunnel through the northern end of the cavern about sixty feet from the first cells of the Beehive.

I am anxious for the passage to be made, for who knows but what it may be the way to freedom for me? Ah! if I only knew how to swim, perhaps I should have attempted to escape through the submarine tunnel, as since it was disclosed by the lashing back of the waters by the whale in its death-struggle, I know exactly where the orifice is situated. It seems to me that at the time of the great tides, this orifice must be partly uncovered. At the full and new moon, when the sea attains its maximum depression below the normal level, it is possible that—I must satisfy myself about this.

I do not know how the fact will help me in any way, even if the entrance to the tunnel is partly uncovered, but I cannot afford to miss any detail that may possibly aid in my escape from Back Cup.

August 29.—This morning I am witnessing the departure of the tug. The Count d'Artigas is, no doubt, going off in the Ebba to fetch the sections of Thomas Roch's engines. Before embarking, the Count converses long and earnestly with Engineer Serko, who, apparently, is not going to accompany him on this trip, and is evidently giving him some recommendations, of which I may be the object. Then, having stepped on to the platform, he goes below, the lid shuts with a bang, and the tug sinks out of sight, leaving a trail of bubbles behind it.

The hours go by, night is coming on, yet the tug does not return. I conclude that it has gone to tow the schooner, and perhaps to destroy any merchant vessels that may come in their way.

It cannot, however, be absent very long, as the trip to America and back will not take more than a week.

Besides, if I can judge from the calm atmosphere in the interior of the cavern, the Ebba must be favored with beautiful weather. This is, in fact, the fine season in this part of the world. Ah! if only I could break out of my prison!



CHAPTER XIII.

GOD BE WITH IT.

From August 29 to September 10.—Thirteen days have gone by and the Ebba has not returned. Did she then not make straight for the American coast? Has she been delayed by a buccaneering cruise in the neighborhood of Back Cup? It seems to me that Ker Karraje's only desire would be to get back with the sections of Roch's engines as soon as possible. Maybe the Virginian foundry had not quite finished them.

Engineer Serko does not display the least anxiety or impatience. He continues to greet me with his accustomed ironical cordiality, and with a kindly air that I distrust—with good reason. He affects to be solicitous as to my health, urges me to make the best of a bad job, calls me Ali Baba, assures me that there is not, in the whole world, such an enchanting spot as this Arabian Nights cavern, observes that I am fed, warmed, lodged, and clothed, that I have no taxes to pay, and that even the inhabitants of the favored principality of Monaco do not enjoy an existence more free from care.

Sometimes this ironical verbiage brings the blood to my face, and I am tempted to seize this cynical banterer by the throat and choke the life out of him. They would kill me afterwards. Still, what would that matter! Would it not be better to end in this way than to spend years and years amid these infernal and infamous surroundings? However, while there is life there is hope, I reflect, and this thought restrains me.

I have scarcely set eyes upon Thomas Roch since the Ebba went away. He shuts himself up in his laboratory and works unceasingly. If he utilizes all the substances placed at his disposition there will be enough to blow up Back Cup and the whole Bermudan archipelago with it!

I cling to the hope that he will never consent to give up the secret of his deflagrator, and that Engineer Serko's efforts to acquire it will remain futile.

September 3.—To-day I have been able to witness with my own eyes the power of Roch's explosive, and also the manner in which the fulgurator is employed.

During the morning the men began to pierce the passage through the wall of the cavern at the spot fixed upon by Engineer Serko, who superintended the work in person. The work began at the base, where the rock is as hard as granite. To have continued it with pickaxes would have entailed long and arduous labor, inasmuch as the wall at this place is not less than from twenty to thirty yards in thickness, but thanks to Roch's fulgurator the passage will be completed easily and rapidly.

I may well be astonished at what I have seen. The pickaxes hardly made any impression on the rock, but its disaggregation was effected with really remarkable facility by means of the fulgurator.

A few grains of this explosive shattered the rocky mass and reduced it to almost impalpable powder that one's breath could disperse as easily as vapor. The explosion produced an excavation measuring fully a cubic yard. It was accompanied by a sharp detonation that may be compared to the report of a cannon.

The first charge used, although a very small one, a mere pinch, blew the men in every direction, and two of them were seriously injured. Engineer Serko himself was projected several yards, and sustained some rather severe contusions.

Here is how this substance, whose bursting force surpasses anything hitherto conceived, is employed.

A small hole about an inch and a half in length is pierced obliquely in the rock. A few grains of the explosive are then inserted, but no wad is used.

Then Thomas Roch steps forward. In his hand is a little glass phial containing a bluish, oily liquid that congeals almost as soon as it comes in contact with the air. He pours one drop on the entrance of the hole, and draws back, but not with undue haste. It takes a certain time—about thirty-five seconds, I reckon—before the combination of the fulgurator and deflagrator is effected. But when the explosion does take place its power of disaggregation is such—I repeat—that it may be regarded as unlimited. It is at any rate a thousand times superior to that of any known explosive.

Under these circumstances it will probably not take more than a week to complete the tunnel.

September 19.—For some time past I have observed that the tide rises and falls twice every twenty-four hours, and that the ebb and flow produce a rather swift current through the submarine tunnel. It is pretty certain therefore that a floating object thrown into the lagoon when the top of the orifice is uncovered would be carried out by the receding tide. It is just possible that during the lowest equinoctial tides the top of the orifice is uncovered. This I shall be able to ascertain, as this is precisely the time they occur. To-day, September 19, I could almost distinguish the summit of the hole under the water. The day after to-morrow, if ever, it will be uncovered.

Very well then, if I cannot myself attempt to get through, may be a bottle thrown into the lagoon might be carried out during the last few minutes of the ebb. And might not this bottle by chance—an ultra-providential chance, I must avow—be picked up by a ship passing near Back Cup? Perhaps even it might be borne away by a friendly current and cast upon one of the Bermudan beaches. What if that bottle contained a letter?

I cannot get this thought out of my mind, and it works me up into a great state of excitement. Then objections crop up—this one among others: the bottle might be swept against the rocks and smashed ere ever it could get out of the tunnel. Very true, but what if, instead of a bottle a diminutive, tightly closed keg were used? It would not run any danger of being smashed and would besides stand a much better chance of reaching the open sea.

September 20.—This evening, I, unperceived, entered one of the store houses containing the booty pillaged from various ships and procured a keg very suitable for my experiment.

I hid the keg under my coat, and returned to the Beehive and my cell. Then without losing an instant I set to work. Paper, pen, ink, nothing was wanting, as will be supposed from the fact that for three months I have been making notes and dotting down my impressions daily.

I indite the following message:

"On June 15 last Thomas Roch and his keeper Gaydon, or rather Simon Hart, the French engineer who occupied Pavilion No. 17, at Healthful House, near New-Berne, North Carolina, United States of America, were kidnapped and carried on board the schooner Ebba, belonging to the Count d'Artigas. Both are now confined in the interior of a cavern which serves as a lair for the said Count d'Artigas—who is really Ker Karraje, the pirate who some time ago carried on his depredations in the West Pacific—and for about a hundred men of which his band is composed.

"When he has obtained possession of Roch's fulgurator whose power is, so to speak, without limit, Ker Karraje will be in a position to carry on his crimes with complete impunity.

"It is therefore urgent that the states interested should destroy his lair without delay.

"The cavern in which the pirate Ker Karraje has taken refuge is in the interior of the islet of Back Cup, which is wrongly regarded as an active volcano. It is situated at the western extremity of the archipelago of Bermuda, and on the east is bounded by a range of reefs, but on the north, south, and west is open.

"Communication with the inside of the mountain is only possible through a tunnel a few yards under water in a narrow pass on the west. A submarine apparatus therefore is necessary to effect an entrance, at any rate until a tunnel they are boring through the northwestern wall of the cavern is completed.

"The pirate Ker Karraje employs an apparatus of this kind—the submarine boat that the Count d'Artigas ordered of the Cramps and which was supposed to have been lost during the public experiment with it in Charleston Bay. This boat is used not only for the purpose of entering and issuing from Back Cup, but also to tow the schooner and attack merchant vessels in Bermudan waters.

"This schooner Ebba, so well known on the American coast, is kept in a small creek on the western side of the island, behind a mass of rocks, and is invisible from the sea.

"The best place to land is on the west coast formerly occupied by the colony of Bermudan fishers; but it would first be advisable to effect a breach in the side of the cavern by means of the most powerful melinite shells.

"The fact that Ker Karraje may be in the position to use Roch's fulgurator for the defence of the island must also be taken into consideration. Let it be well borne in mind that if its destructive power surpasses anything ever conceived or dreamed of, it extends over a zone not exceeding a mile in extent. The distance of this dangerous zone is variable, but once the engines have been set, the modification of the distance occupies some time, and a warship that succeeds in passing the zone has nothing further to fear.

"This document is written on the twentieth day of September at eight o'clock in the evening and is signed with my name

"THOMAS HART, Engineer."

The above is the text of the statement I have just drawn up. It says all that is necessary about the island, whose exact situation is marked on all modern charts and maps, and points out the expediency of acting without delay, and what to do in case Ker Karraje is in the position to employ Roch's fulgurator.

I add a plan of the cavern showing its internal configuration, the situation of the lagoon, the lay of the Beehive, Ker Karraje's habitation, my cell, and Thomas Roch's laboratory.

I wrap the document in a piece of tarpaulin and insert the package in the little keg, which measures six inches by three and a half. It is perfectly watertight and will stand any amount of knocking about against the rocks.

There is one danger, however, and that is, that it may be swept back by the returning tide, cast up on the island, and fall into the hands of the crew of the Ebba when the schooner is hauled into her creek. If Ker Karraje ever gets hold of it, it will be all up with me.

It will be readily conceived with what anxiety I have awaited the moment to make the attempt: I am in a perfect fever of excitement, for it is a matter of life or death to me. I calculate from previous observations that the tide will be very low at about a quarter to nine. The top of the tunnel ought then to be a foot and a half above water, which is more than enough to permit of the keg passing through it. It will be another half hour at least before the flow sets in again, and by that time the keg may be far enough away to escape being thrown back on the coast.

I peer out of my cell. There is no one about, and I advance to the side of the lagoon, where by the light of a nearby lamp, I perceive the arch of the tunnel, towards which the current seems to be setting pretty swiftly.

I go down to the very edge, and cast in the keg which contains the precious document and all my hopes.

"God be with it!" I fervently exclaim. "God be with it!"

For a minute or two the little barrel remains stationary, and then floats back to the side again. I throw it out once more with all my strength.

This time it is in the track of the current, which to my great joy sweeps it along and in twenty seconds, it has disappeared in the tunnel.

Yes, God be with it! May Heaven guide thee, little barrel! May it protect all those whom Ker Karraje menaces and grant that this band of pirates may not escape from the justice of man!



CHAPTER XIV.

BATTLE BETWEEN THE "SWORD" AND THE TUG.

Through all this sleepless night I have followed the keg in fancy. How many times I seem to see it swept against the rocks in the tunnel into a creek, or some excavation. I am in a cold perspiration from head to foot. Then I imagine that it has been carried out to sea. Heavens! if the returning tide should sweep it back to the entrance and then through the tunnel into the lagoon! I must be on the lookout for it.

I rise before the sun and saunter down to the lagoon. Not a single object is floating on its calm surface.

The work on the tunnel through the side of the cavern goes on, and at four o'clock in the afternoon on September 23, Engineer Serko blows away the last rock obstructing the issue, and communication with the outer world is established. It is only a very narrow hole, and one has to stoop to go through it. The exterior orifice is lost among the crannies of the rocky coast, and it would be easy to obstruct it, if such a measure became necessary.

It goes without saying that the passage will be strictly guarded. No one without special authorization will be able either to go out or come in, therefore there is little hope of escape in that direction.

September 25.—This morning the tug rose from the depth of the lagoon to the surface, and has now run alongside the jetty. The Count d'Artigas and Captain Spade disembark, and the crew set to work to land the provisions—boxes of canned meat, preserves, barrels of wine and spirits, and other things brought by the Ebba, among which are several packages destined for Thomas Roch. The men also land the various sections of Roch's engines which are discoid in shape.

The inventor watches their operations, and his eyes glisten with eagerness. He seizes one of the sections, examines it, and nods approval. I notice that his joy no longer finds expression in incoherent utterances, that he is completely transformed from what he was while a patient at Healthful House. So much is this the case that I begin to ask myself whether his madness which was asserted to be incurable, has not been radically cured.

At last Thomas Roch embarks in the boat used for crossing the lake and is rowed over to his laboratory. Engineer Serko accompanies him. In an hour's time the tug's cargo has all been taken out and transported to the storehouses.

Ker Karraje exchanges a word or two with Engineer Serko and then enters his mansion. Later, in the afternoon, I see them walking up and down in front of the Beehive and talking earnestly together.

Then they enter the new tunnel, followed by Captain Spade. If I could but follow them! If I could but breathe for awhile the bracing air of the Atlantic, of which the interior of Back Cup only receives attenuated puffs, so to speak.

From September 26 to October 10.—Fifteen days have elapsed. Under the directions of Engineer Serko and Thomas Roch the sections of the engines have been fitted together. Then the construction of their supports is begun. These supports are simple trestles, fitted with transverse troughs or grooves of various degrees of inclination, and which could be easily installed on the deck of the Ebba, or even on the platform of the tug, which can be kept on a level with the surface.

Thus Ker Karraje, will be ruler of the seas, with his yacht. No warship, however big, however powerful, will be able to cross the zone of danger, whereas the Ebba will be out of range of its guns. If only my notice were found! If only the existence of this lair of Back Cup were known! Means would soon be found, if not of destroying the place, at least of starving the band into submission!

October 20.—To my extreme surprise I find this morning that the tug has gone away again. I recall that yesterday the elements of the piles were renewed, but I thought it was only to keep them in order. In view of the fact that the outside can now be reached through the new tunnel, and that Thomas Roch has everything he requires, I can only conclude that the tug has gone off on another marauding expedition.

Yet this is the season of the equinoctial gales, and the Bermudan waters are swept by frequent tempests. This is evident from the violent gusts that drive back the smoke through the crater and the heavy rain that accompanies it, as well as by the water in the lagoon, which swells and washes over the brown rocks on its shores.

But it is by no means sure that the Ebba has quitted her cove. However staunch she may be, she is, it seems to me, of too light a build to face such tempests as now rage, even with the help of the tug.

On the other hand, although the tug has nothing to fear from the heavy seas, as it would be in calm water a few yards below the surface, it is hardly likely that it has gone on a trip unless to accompany the schooner.

I do not know to what its departure can be attributed, but its absence is likely to be prolonged, for it has not yet returned.

Engineer Serko has remained behind, but Ker Karraje, Captain Spade, and the crew of the schooner, I find, have left.

Life in the cavern goes on with its usual dispiriting monotony. I pass hour after hour in my cell, meditating, hoping, despairing, following in fancy the voyage of my little barrel, tossed about at the mercy of the currents and whose chances of being picked up, I fear, are becoming fainter each day, and killing time by writing my diary, which will probably not survive me.

Thomas Roch is constantly occupied in his laboratory manufacturing his deflagrator. I still entertain the conviction that nothing will ever induce him to give up the secret of the liquid's composition; but I am perfectly aware that he will not hesitate to place his invention at Ker Karraje's service.

I often meet Engineer Serko when my strolls take me in the direction of the Beehive. He always shows himself disposed to chat with me, though, it is true, he does so in a tone of impertinent frivolity. We converse upon all sorts of subjects, but rarely of my position. Recrimination thereanent is useless and only subjects me to renewed bantering.

October 22.—To-day I asked Engineer Serko whether the Ebba had put to sea again with the tug.

"Yes, Mr. Simon Hart," he replied, "and though the clouds gather and loud the tempest roars, be in no uneasiness in regard to our dear Ebba."

"Will she be gone long?"

"We expect her back within forty-eight hours. It is the last voyage Count d'Artigas proposes to make before the winter gales render navigation in these parts impracticable."

"Is her voyage one of business or pleasure?"

"Of business, Mr. Hart, of business," answered Engineer Serko with a smile. "Our engines are now completed, and when the fine weather returns we shall resume offensive operations."

"Against unfortunate merchantmen."

"As unfortunate as they are richly laden."

"Acts of piracy, whose impunity will, I trust, not always be assured," I cried..

"Calm yourself, dear colleague, be calm! Be calm! No one, you know, can ever discover our retreat, and none can ever disclose the secret! Besides, with these engines, which are so easily handled and are of such terrible power, it would be easy for us to blow to pieces any ship that attempted to get within a certain radius of the island."

"Providing," I said, "that Thomas Roch has sold you the composition of his deflagrator as he has sold you that of his fulgurator."

"That he has done, Mr. Hart, and it behooves me to set your mind at rest upon that point."

From this categorical response I ought to have concluded that the misfortune had been consummated, but a certain hesitation in the intonation of his voice warned me that implicit reliance was not to be placed upon Engineer Serko's assertions.

October 25.—What a frightful adventure I have just been mixed up in, and what a wonder I did not lose my life! It is only by a miracle that I am able to resume these notes, which have been interrupted for forty-eight hours. With a little luck, I should have been delivered! I should now be in one of the Bermudan ports—St. George or Hamilton. The mysteries of Back Cup would have been cleared up. The description of the schooner would have been wired all over the world, and she would not dare to put into any port. The provisioning of Back Cup would be impossible, and Ker Karraje's bandits would be condemned to starve to death!

This is what occurred:

At eight o'clock in the evening on October 23, I quitted my cell in an indefinable state of nervousness, and with a presentiment that a serious event was imminent. In vain I had tried to seek calmness in sleep. It was impossible to do so, and I rose and went out.

Outside Back Cup the weather must have been very rough. Violent gusts of wind swept in through the crater and agitated the water of the lagoon.

I walked along the shore on the Beehive side. No one was about. It was rather cold, and the air was damp. The pirates were all snugly ensconced in their cells, with the exception of one man, who stood guard over the new passage, notwithstanding that the outer entrance had been blocked. From where he was this man could not see the lagoon, moreover there were only two lamps alight, one on each side of the lake, and the forest of pillars was wrapt in the profoundest obscurity.

I was walking about in the shadow, when some one passed me.

I saw that he was Thomas Roch.

He was walking slowly, absorbed by his thoughts, his brain at work, as usual.

Was this not a favorable opportunity to talk to him, to enlighten him about what he was probably ignorant, namely, the character of the people into whose hands he had fallen?

"He cannot," I argued, "know that the Count d'Artigas is none other than Ker Karraje, the pirate. He cannot be aware that he has given up a part of his invention to such a bandit. I must open his eyes to the fact that he will never be able to enjoy his millions, that he is a prisoner in Back Cup, and will never be allowed to leave it, any more than I shall. Yes, I will make an appeal to his sentiments of humanity, and point out to him what frightful misfortunes he will be responsible for if he does not keep the secret of his deflagrator."

All this I had said to myself, and was preparing to carry out my resolution, when I suddenly felt myself seized from behind.

Two men held me by the arms, and another appeared in front of me.

Before I had time to cry out the man exclaimed in English:

"Hush! not a word! Are you not Simon Hart?"

"Yes, how did you know?"

"I saw you come out of your cell."

"Who are you, then?"

"Lieutenant Davon, of the British Navy, of H.M.S. Standard, which is stationed at the Bermudas."

Emotion choked me so that it was impossible for me to utter a word.

"We have come to rescue you from Ker Karraje, and also propose to carry off Thomas Roch," he added.

"Thomas Roch?" I stammered.

"Yes, the document signed by you was found on the beach at St. George——"

"In a keg, Lieutenant Davon, which I committed to the waters of the lagoon."

"And which contained," went on the officer, "the notice by which we were apprised that the island of Back Cup served as a refuge for Ker Karraje and his band—Ker Karraje, this false Count d'Artigas, the author of the double abduction from Healthful House."

"Ah! Lieutenant Davon——"

"Now we have not a moment to spare, we must profit by the obscurity."

"One word, Lieutenant Davon, how did you penetrate to the interior of Back Cup?"

"By means of the submarine boat Sword, with which we have been making experiments at St. George for six months past."

"A submarine boat!"

"Yes, it awaits us at the foot of the rocks. And now, Mr. Hart, where is Ker Karraje's tug?"

"It has been away for three weeks."

"Ker Karraje is not here, then?"

"No, but we expect him back every day—every hour, I might say."

"It matters little," replied Lieutenant Davon. "It is not after Ker Karraje, but Thomas Roch, we have come—and you also, Mr. Hart. The Sword will not leave the lagoon till you are both on board. If she does not turn up at St. George again, they will know that I have failed—and they will try again."

"Where is the Sword, Lieutenant?"

"On this side, in the shadow of the bank, where it cannot be seen. Thanks to your directions, I and my crew were able to locate the tunnel. We came through all right, and ten minutes ago rose to the surface of the lake. Two men landed with me. I saw you issue from the cell marked on your plan. Do you know where Thomas Roch is?"

"A few paces off. He has just passed me, on his way to his laboratory."

"God be praised, Mr. Hart!"

"Amen, Lieutenant Davon."

The lieutenant, the two men and I took the path around the lagoon. We had not gone far when we perceived Thomas Roch in front of us. To throw ourselves upon him, gag him before he could utter a cry, bind him before he could offer any resistance, and bear him off to the place where the Sword was moored was the work of a minute.

The Sword was a submersible boat of only twelve tons, and consequently much inferior to the tug, both in respect of dimensions and power. Her screw was worked by a couple of dynamos fitted with accumulators that had been charged twelve hours previously in the port of St. George. However, the Sword would suffice to take us out of this prison, to restore us to liberty—that liberty of which I had given up all hope. Thomas Roch was at last to be rescued from the clutches of Ker Karraje and Engineer Serko. The rascals would not be able to utilize his invention, and nothing could prevent the warships from landing a storming party on the island, who would force the tunnel in the wall and secure the pirates!

We saw no one while the two men were conveying Thomas Roch to the Sword, and all got on board without incident. The lid was shut and secured, the water compartments filled, and the Sword sank out of sight. We were saved!

The Sword was divided into three water-tight compartments. The after one contained the accumulators and machinery. The middle one, occupied by the pilot, was surmounted by a periscope fitted with lenticular portholes, through which an electric search-lamp lighted the way through the water. Forward, in the other compartment, Thomas Roch and I were shut in.

My companion, though the gag which was choking him had been removed, was still bound, and, I thought, knew what was going on.

But we were in a hurry to be off, and hoped to reach St. George that very night if no obstacle was encountered.

I pushed open the door of the compartment and rejoined Lieutenant Davon, who was standing by the man at the wheel. In the after compartment three other men, including the engineer, awaited the lieutenant's orders to set the machinery in motion.

"Lieutenant Davon," I said, "I do not think there is any particular reason why I should stay in there with Roch. If I can help you to get through the tunnel, pray command me."

"Yes, I shall be glad to have you by me, Mr. Hart."

It was then exactly thirty-seven minutes past eight.

The search-lamp threw a vague light through the water ahead of the Sword. From where we were, we had to cross the lagoon through its entire length to get to the tunnel. It would be pretty difficult to fetch it, we knew, but, if necessary, we could hug the sides of the lake until we located it. Once outside the tunnel the Sword would rise to the surface and make for St. George at full speed.

"At what depth are we now?" I asked the lieutenant.

"About a fathom."

"It is not necessary to go any lower," I said. "From what I was able to observe during the equinoctial tides, I should think that we are in the axis of the tunnel."

"All right," he replied.

Yes, it was all right, and I felt that Providence was speaking by the mouth of the officer. Certainly Providence could not have chosen a better agent to work its will.

In the light of the lamp I examined him. He was about thirty years of age, cool, phlegmatic, with resolute physiognomy—the English officer in all his native impassibility—no more disturbed than if he had been on board the Standard, operating with extraordinary sang-froid, I might even say, with the precision of a machine.

"On coming through the tunnel I estimated its length at about fifty yards," he remarked.

"Yes, Lieutenant, about fifty yards from one extremity to the other."

This calculation must have been pretty exact, since the new tunnel cut on a level with the coast is thirty-five feet in length.

The order was given to go ahead, and the Sword moved forward very slowly for fear of colliding against the rocky side.

Sometimes we came near enough to it to distinguish a black mass ahead of it, but a turn of the wheel put us in the right direction again. Navigating a submarine boat in the open sea is difficult enough. How much more so in the confines of a lagoon!

After five minutes' manoeuvring, the Sword, which was kept at about a fathom below the surface, had not succeeded in sighting the orifice.

"Perhaps it would be better to return to the surface, Lieutenant," I said. "We should then be able to see where we are."

"I think you are right, Mr. Hart, if you can point out just about where the tunnel is located."

"I think I can."

"Very well, then."

As a precaution the light was turned off. The engineer set the pumps in motion, and, lightened of its water ballast, the boat slowly rose in the darkness to the surface.

I remained at my post so that I could peer through the lookouts.

At last the ascensional movement of the Sword stopped, and the periscope emerged about a foot.

On one side of me, lighted by the lamp by the shore, I could see the Beehive.

"What is your opinion?" demanded the lieutenant.

"We are too far north. The orifice is in the west side of the cavern."

"Is anybody about?"

"Not a soul."

"Capital, Mr. Hart. Then we will keep on a level with the surface, and when we are in front of the tunnel, and you give the signal, we will sink."

It was the best thing to be done. We moved off again and the pilot kept her head towards the tunnel.

When we were about twelve yards off I gave the signal to stop. As soon as the current was turned off the Sword stopped, opened her water tanks and slowly sank again.

Then the light in the lookout was turned on again, and there in front of us was a black circle that did not reflect the lamp's rays.

"There it is, there is the tunnel!" I cried.

Was it not the door by which I was going to escape from my prison? Was not liberty awaiting me on the other side?

Gently the Sword moved towards the orifice.

Oh! the horrible mischance! How have I survived it? How is it that my heart is not broken?

A dim light appeared in the depth of the tunnel, about twenty-five yards in front of us. The advancing light could be none other than that, projected through the lookout of Ker Karraje's submarine boat.

"The tug! The tug!" I exclaimed. "Lieutenant, here is the tug returning to Back Cup!"

"Full speed astern," ordered the officer, and the Sword drew back just as she was about to enter the tunnel.

One chance remained. The lieutenant had swiftly turned off the light, and it was just possible that we had not been seen by the people in the tug. Perhaps, in the dark waters of the lagoon, we should escape notice, and when the oncoming boat had risen and moored to the jetty, we should be able to slip out unperceived.

We had backed close in to the south side and the Sword was about to stop, but alas, for our hopes! Captain Spade had seen that another submarine boat was about to issue through the tunnel, and he was making preparations to chase us. How could a frail craft like the Sword defend itself against the attacks of Ker Karraje's powerful machine?

Lieutenant Davon turned to me and said: "Go back to the compartment where Thomas Roch is and shut yourself in. I will close the after-door. There is just a chance that if the tug rams us the water-tight compartments will keep us up."

After shaking hands with the lieutenant, who was as cool as though we were in no danger, I went forward and rejoined Thomas Roch. I closed the door and awaited the issue in profound darkness.

Then I could feel the desperate efforts made by the Sword to escape from or ram her enemy. I could feel her rushing, gyrating and plunging. Now she would twist to avoid a collision. Now she would rise to the surface, then sink to the bottom of the lagoon. Can any one conceive such a struggle as that in which, like two marine monsters, these machines were engaged in beneath the troubled waters of this inland lake?

A few minutes elapsed, and I began to think that the Sword had eluded the tug and was rushing through the tunnel.

Suddenly there was a collision. The shock was not, it seemed to me, very violent, but I could be under no illusion: the Sword had been struck on her starboard quarter. Perhaps her plates had resisted, and if not, the water would only invade one of her compartments, I thought.

Almost immediately after, however, there was another shock that pushed the Sword with extreme violence. She was raised by the ram of the tug which sawed and ripped its way into her side. Then I could feel her heel over and sink straight down, stern foremost.

Thomas Roch and I were tumbled over violently by. this movement. There was another bump, another ripping sound, and the Sword lay still.

Just what happened after that I am unable to say, for I lost consciousness.

I have since learned that all this occurred many hours ago.

I however distinctly remember that my last thought was:

"If I am to die, at any rate Thomas Roch and his secret perish with me—and the pirates of Back Cup will not escape punishment for their crimes."



CHAPTER XV.

EXPECTATION.

As soon as I recover my senses I find myself lying on my bed in my cell, where it appears I have been lying for thirty-six hours.

I am not alone. Engineer Serko is near me. He has attended to me himself, not because he regards me as a friend, I surmise, but as a man from whom indispensable explanations are awaited, and who afterwards can be done away with if necessary.

I am still so weak that I could not walk a step. A little more and I should have been asphyxiated in that narrow compartment of the Sword at the bottom of the lagoon.

Am I in condition to reply to the questions that Engineer Serko is dying to put to me? Yes—but I shall maintain the utmost reserve.

In the first place I wonder what has become of Lieutenant Davon and the crew of the Sword. Did those brave Englishmen perish in the collision? Are they safe and sound like us—for I suppose that Thomas Roch has also survived?

The first question that Engineer Serko puts to me is this:

"Will you explain to me what happened, Mr. Hart?"

Instead of replying it occurs to me to question him myself.

"And Thomas Roch?" I inquire.

"In good health, Mr. Hart." Then he adds in an imperious tone: "Tell me what occurred!"

"In the first place, tell me what became of the others."

"What others?" replies Serko, glancing at me savagely.

"Why, those men who threw themselves upon Thomas Roch and me, who gagged, bound, and carried us off and shut us up, I know not where?"

On reflection I had come to the conclusion that the best thing to do was to pretend that I had been surprised before I knew where I was or who my aggressors were.

"You will know what became of them later. But first, tell me how, the thing was done."

By the threatening tone of his voice, as he for the third time puts this question, I understand the nature of the suspicions entertained of me. Yet to be in the position to accuse me of having had relations with the outside he would have had to get possession of my keg. This he could not have done, seeing that it is in the hands of the Bermudan authorities. The pirates cannot, I am convinced, have a single proof to back up their suspicions.

I therefore recount how about eight o'clock on the previous evening I was walking along the edge of the lagoon, after Thomas Roch had passed me, going towards his laboratory, when I felt myself seized from behind; how having been gagged, bound, and blindfolded, I felt myself carried off and lowered into a hole with another person whom I thought I recognized from his groans as Thomas Roch; how I soon felt that I was on board a boat of some description and naturally concluded that it was the tug; how I felt it sink; how I felt a shock that threw me violently against the side, and how I felt myself suffocating and lost consciousness, since I remember nothing further.

Engineer Serko listens with profound attention, a stern look in his eyes and a frown on his brow; and yet he can have no reason that authorizes him to doubt my word.

"You claim that three men threw themselves upon you?" he asks.

"Yes. I thought they were some of your people, for I did not see them coming. Who were they?"

"Strangers, as you must have known from their language."

"They did not utter a word!"

"Have you no idea as to their nationality?"

"Not the remotest."

Do you know what were their intentions in entering the cavern?"

"I do not."

"What is your opinion about it?"

"My opinion, Mr. Serko? I repeat I thought they were two or three of your pirates who had come to throw me into the lagoon by the Count d'Artigas' orders, and that they were going to do the same thing to Thomas Roch. I supposed that having obtained his secrets—as you informed me was the case—you had no further use for him and were about to get rid of us both."

"Is it possible, Mr. Hart, that you could have thought such a thing!" continued Serko in his sarcastic way.

"I did, until having been able to remove the bandage from my eyes, I perceived that I was in the tug."

"It was not the tug, but a boat of the same kind that had got through the tunnel."

"A submarine boat?" I ejaculate.

"Yes, and manned by persons whose mission was to kidnap you and Thomas Roch."

"Kidnap us?" I echo, continuing to feign surprise.

"And," adds Engineer Serko, "I want to know what you think about the matter."

"What I think about it? Well, it appears to me that there is only one plausible explanation possible. If the secret of your retreat has not been betrayed—and I cannot conceive how you could have been betrayed or what imprudence you or yours could have committed—my opinion is that this submarine boat was exploring the bottom of the sea in this neighborhood, that she must have found her way into the tunnel, that she rose to the surface of the lagoon, that her crew, greatly surprised to find themselves inside an inhabited cavern, seized hold of the first persons they came across, Thomas Roch and myself, and others as well perhaps, for of course I do not know——"

Engineer Serko has become serious again. Does he realize the inanity of the hypothesis I try to pass off on him? Does he think I know more than I will say? However this may be, he accepts my professed view, and says:

"In effect, Mr. Hart, it must have happened as you suggest, and when the stranger tried to make her way out through the tunnel just as the tug was entering, there was a collision—a collision of which she was the victim. But we are not the kind of people to allow our fellow-men to perish before our eyes. Moreover, the disappearance of Thomas Roch and yourself was almost immediately discovered. Two such valuable lives had to be saved at all hazards. We set to work. There are many expert divers among our men. They hastily donned their suits and descended to the bottom of the lagoon. They passed lines around the hull of the Sword——"

"The Sword?" I exclaim.

"That is the name we saw painted on the bow of the vessel when we raised her to the surface. What satisfaction we experienced when we recovered you—unconscious, it is true, but still breathing—and were able to bring you back to life! Unfortunately all our attentions to the officer who commanded the Sword, and to his crew were useless. The shock had torn open the after and middle compartments, and they paid with their lives the misfortune—due to chance, as you observe—of having discovered our mysterious retreat."

On learning that Lieutenant Davon and his companions are dead, my heart is filled with anguish; but to keep up my role—as they were persons with whom, presumably, I was not acquainted, and had never seen—I am careful not to display any emotion. I must, on no account, afford ground for the suspicion that there was any connivance between the commander of the Sword and me. For aught I know, Engineer Serko may have reason to be very skeptical about the discovery of the tunnel being accidental.

What, however, I am most concerned about is that the unlooked-for occasion to recover my liberty was lost. Shall I ever be afforded another chance? However this may be, my notice reached the English authorities of the archipelago, and they now know where Ker Karraje is to be found. When it is seen that the Sword does not return to Bermuda, there can be no doubt that another attempt will be made to get inside Back Cup, in which, had it not been for the inopportune return of the tug, I should no longer be a prisoner.

I have resumed my usual existence, and having allayed all mistrust, am permitted to wander freely about the cavern, as usual.

It is patent that the adventure has had no ill effect upon Thomas Roch. Intelligent nursing brought him around, as it did me. In full possession of his mental faculties he has returned to work, and spends the entire day in his laboratory.

The Ebba brought back from her last trip bales, boxes, and a quantity of objects of varied origin, and I conclude that a number of ships must have been pillaged during this marauding expedition.

The work on the trestles for Roch's engine goes steadily forward, and there are now no fewer than fifty engines. If Ker Karraje and Engineer Serko are under the necessity of defending Back Cup, three or four will be sufficient to render the island unapproachable, as they will cover a zone which no vessel could enter without being blown to pieces. And it occurs to me that they intend to put Back Cup in a state of defence after having argued as follows:

"If the appearance of the Sword in the lagoon was due to chance the situation remains unchanged, and no power, not even England, will think of seeking for the Sword inside the cavern. If, on the other hand, as the result of an incomprehensible revelation, it has been learned that Back Cup is become the retreat of Ker Karraje, if the expedition of the Sword was a first effort against the island, another of a different kind—either a bombardment from a distance, or an attack by a landing party—is to be expected. Therefore, ere we can quit Back Cup and carry away our plunder, we shall have to defend ourselves by means of Roch's fulgurator."