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.”

in my opinion the rascals must have gone on to reason still further in this wise:

“is there any connection between the disclosure of our secret—if it was, and however it may have been made—and the double abduction from healthful house? is it known that thomas roch and his keeper are confined in back cup? is it known that the abduction was effected in the interest of ker karraje? have americans, english, french, germans, and russians reason to fear that an attack in force against the island would be doomed to failure?”

ker karraje must know very well that these powers would not hesitate to attack him, however great the danger might be. the destruction of his lair is an urgent duty in the interest of public security and of humanity. after sweeping the west pacific the pirate and his companions are infesting the west atlantic, and must be wiped out at all costs.

in any case, it is imperative that the inhabitants of back cup should be on their guard. this fact is realized, and, from the day on which the sword was destroyed, strict watch has been kept. thanks to the new passage, they are able to hide among the rocks without having recourse to the submarine tunnel to get there, and day and night a dozen sentries are posted about the island. the moment a ship appears in sight the fact is at once made known inside the cavern.

nothing occurs for some days, and the latter succeed each other with dreadful monotony. the pirates, however, feel that back cup no longer enjoys its former security. every moment an alarm from the sentries posted outside is expected. the situation is no longer the same since the advent of the sword. gallant lieutenant davon, gallant crew, may england, may the civilized nations, never forget that you have sacrificed your lives in the cause of humanity!

it is evident that now, however powerful may be their means of defence, even more powerful than a network of torpedoes, engineer serko and captain spade are filled with an anxiety that they vainly essay to dissemble. they hold frequent conferences together. maybe they discuss the advisability of quitting back cup with their wealth, for they are aware that if the existence of the cavern is known means will be found to reduce it, even if the inmates have to be starved out.

this is, of course, mere conjecture on my part. what is essential to me is that they do not suspect me of having launched the keg that was so providentially picked up at bermuda. never, i must say, has engineer serko ever made any allusion to any such probability. no, i am not even suspected. if the contrary were the case i am sufficiently acquainted with ker karraje to know that he would long ago have sent me to rejoin lieutenant davon and the sword at the bottom of the lagoon.

the winter tempests have set in with a vengeance. the wind howls though the hole in the roof, and rude gusts sweep through the forest of pillars producing sonorous sounds, so sonorous, so deep, that one might sometimes almost fancy they were produced by the firing of the guns of a squadron. flocks of seabirds take refuge in the cavern from the gale, and at intervals, when it lulls, almost deafen us with their screaming.

it is to be presumed that in such weather the schooner will make no attempt to put to sea, for the stock of provisions is ample enough to last all the season. moreover, i imagine the count d’artigas will not be so eager in future to show his ebba along the american coast, where he risks being received, not, as hitherto, with the consideration due to a wealthy yachtsman, but in the manner ker karraje so richly merits.

it occurs to me that if the apparition of the sword was the commencement of a campaign against the island, a question of great moment relative to the future of back cup arises.

therefore, one day, prudently, so as not to excite any suspicion, i ventured to pump engineer serko about it.

we were in the neighborhood of thomas roch’s laboratory, and had been conversing for some time, when engineer serko touched upon the extraordinary apparition of an english submarine boat in the lagoon. on this occasion he seemed to incline to the view that it might have been a premeditated expedition against ker karraje.

“that is not my opinion,” i replied, in order to bring him to the question that i wanted to put to him.

“why?” he demanded.

“because if your retreat were known a fresh attempt, if not to penetrate to the cavern, at least to destroy back cup, would ere this have been made.”

“destroy it!” cried serko. “it would be a dangerous undertaking, in view of the means of defence of which we now dispose.”

“they can know nothing about this matter, mr. serko. it is not imagined, either in the new world or the old, that the abduction from healthful house was effected for your especial benefit, or that you have succeeded in coming to terms with thomas roch for his invention.”

engineer serko made no response to this observation, which, for that matter, was unanswerable.

i continued:

“therefore a squadron sent by the maritime powers who have an interest in breaking up this island would not hesitate to approach and shell it. now, i argue from this that as this squadron has not yet appeared, it is not likely to come at all, and that nothing is known as to ker karraje’s whereabouts, and you must admit that this hypothesis is the most cheerful one, as far as you are concerned.”

“that may be,” engineer serko replied, “but what is, is. whether they are aware of the fact or no, if warships approach within five or six miles of this island they will be sunk before they have had time to fire a single shot!”

“well, and what then?”

“what then? why the probability is that no others would care to repeat the experiment.”

“that, again, may be. but these warships would invest you beyond the dangerous zone, and the ebba would not be able to put in to the ports she previously visited with the count d’artigas. in this event, how would you be able to provision the island?”

engineer serko remained silent.

this argument, which he must already have brooded over, was too logical to be refuted or dismissed, and i have an idea that the pirates contemplate abandoning back cup.

nevertheless, not relishing being cornered, he continued:

“we should still have the tug, and what the ebba could not do, this would.”

“the tug?” i cried. “but if ker karraje’s secrets are known, do you suppose the powers are not also aware of the existence of the count d’artigas’ submarine boat?”

engineer serko looked at me suspiciously.

“mr. hart,” he said, “you appear to me to carry your deductions rather far.”

“i, mr. serko?”

“yes, and i think you talk about all this like a man who knows more than he ought to.”

this remark brought me up abruptly. it was evident that my arguments might give rise to the suspicion that i was not altogether irresponsible for the recent incident. engineer serko scrutinized me sharply as though he would read my innermost thoughts.

“mr. serko,” i observed, “by profession, as well as by inclination, i am accustomed to reason upon everything. this is why i communicated to you the result of my reasoning, which you can take into consideration or not, as you like.”

thereupon we separate. but i fancy my lack of reserve may have excited suspicions which may not be easy to allay.

from this interview, however, i gleaned a precious bit of information, namely, that the dangerous zone of roch’s fulgurator is between five and six miles off. perhaps, during the next equinoctial tides, another notice to this effect in another keg may also reach a safe destination.

but how many weary months to wait before the orifice of the tunnel will again be uncovered!

the rough weather continues, and the squalls are more violent than ever. is it the state of the sea that delays another campaign against back cup? lieutenant davon certainly assured me that if his expedition failed, if the sword did not return to st. george, another attempt under different conditions would be made with a view to breaking up this bandits’ lair. sooner or later the work of justice must be done, and back cup be destroyed, even though i may not survive its destruction.

ah! why can i not go and breathe, if only for a single instant, the vivifying air outside? why am i not permitted to cast one glance over the ocean towards the distant horizon of the bermudas? my whole life is concentrated in one desire: to get through the tunnel in the wall and hide myself among the rocks. perchance i might be the first to catch sight of the smoke of a squadron heading for the island.

this project, alas! is unrealizable, as sentries are posted day and night at each extremity of the passage. no one can enter it without engineer serko’s authorization. were i to attempt it, i should risk being deprived of my liberty to walk about the cavern, and even worse might happen to me.

since our last conversation, engineer serko’s attitude towards me has undergone a change. his gaze has lost its old-time sarcasm and is distrustful, suspicious, searching and as stern as ker karraje’s.

november 17.—this afternoon there was a great commotion in the beehive, and the men rushed out of their cells with loud cries.

i was reclining on my bed, but immediately rose and hurried out.

all the pirates were making for the passage, in front of which were ker karraje, engineer serko, captain spade, boatswain effrondat, engine-driver gibson and the count d’artigas’ big malay attendant.

i soon learn the reason for the tumult, for the sentries rush in with shouts of alarm.

several vessels have been sighted to the northwest—warships steaming at full speed in the direction of back cup.