"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.