I wonder whether the _Ebba_ will venture to try the dangerous feat of pa.s.sing through it. I do not think so. She will probably lay where she is--though why she should do so I do not know--for a few hours, and then continue her voyage towards the east.

However this may be I see no preparations in progress for dropping anchor. The anchors are suspended in their usual places, the cables have not been cleared, and no motion has been made to lower a single boat.

At this moment Count d'Artigas, Engineer Serko and Captain Spade go forward and perform some manoeuvre that is inexplicable to me.

I walk along the port side of the deck until I am near the foremast, and then I can see a small buoy that the sailors are hoisting in.

Almost immediately the water, at the same spot becomes dark and I observe a black ma.s.s rising to the surface. Is it a big whale rising for air, and is the _Ebba_ in danger of being shattered by a blow from the monster's tail?

Now I understand! At last the mystery is solved. I know what was the motor that caused the schooner to go at such an extraordinary speed without sails and without a screw. Her indefatigable motor is emerging from the sea, after having towed her from the coast of America to the archipelago of the Bermudas. There it is, floating alongside--a submersible boat, a submarine tug, worked by a screw set in motion by the current from a battery of acc.u.mulators or powerful electric piles.

On the upper part of the long cigar-shaped iron tug is a platform in the middle of which is the "lid" by which an entrance is effected. In the fore part of the platform projects a periscope, or lookout, formed by port-holes or lenses through which an electric searchlight can throw its gleam for some distance under water in front of and on each side of the tug. Now relieved of its ballast of water the boat has risen to the surface. Its lid will open and fresh air will penetrate it to every part. In all probability, if it remained submerged during the day it rose at night and towed the _Ebba_ on the surface.

But if the mechanical power of the tug is produced by electricity the latter must be furnished by some manufactory where it is stored, and the means of procuring the batteries is not to be found on Back Cup, I suppose.

And then, why does the _Ebba_ have recourse to this submarine towing system? Why is she not provided with her own means of propulsion, like other pleasure-boats?

These are things, however, upon which I have at present no leisure to ruminate.

The lid of the tug opens and several men issue on to the platform.

They are the crew of this submarine boat, and Captain Spade has been able to communicate with them and transmit his orders as to the direction to be taken by means of electric signals connected with the tug by a wire that pa.s.ses along the stem of the schooner.

Engineer Serko approaches me and says, pointing to the boat:

"Get in."

"Get in!" I exclaim.

"Yes, in the tug, and look sharp about it."

As usual there is nothing for it but to obey. I hasten to comply with the order and clamber over the side.

At the same time Thomas Roch appears on deck accompanied by one of the crew. He appears to be very calm, and very indifferent too, and makes no resistance when he is lifted over and lowered into the tug. When he has been taken in, Count d'Artigas and Engineer Serko follow.

Captain Spade and the crew of the _Ebba_ remain behind, with the exception of four men who man the dinghy, which has been lowered. They have hold of a long hawser, with which the schooner is probably to be towed through the reef. Is there then a creek in the middle of the rocks where the vessel is secure from the breakers? Is this the port to which she belongs?

They row off with the hawser and make the end fast to a ring in the reef. Then the crew on board haul on it and in five minutes the schooner is so completely lost to sight among the rocks that even the tip of her mast could not be seen from the sea.

Who in Bermuda imagines that a vessel is accustomed to lay up in this secret creek? Who in America would have any idea that the rich yachtsman so well known in all the eastern ports abides in the solitude of Back Cup mountain?

Twenty minutes later the dinghy returns with the four men towards the tug which was evidently waiting for them before proceeding--where?

They climb on board, the little boat is made fast astern, a movement is felt, the screw revolves rapidly and the tug skims along the surface to Back Cup, skirting the reefs to the south.

Three cable's lengths further on, another tortuous ca.n.a.l is seen that leads to the island. Into this the tug enters. When it gets close insh.o.r.e, an order is given to two men who jump out and haul the dinghy up on a narrow sandy beach out of the reach of wave or weed, and where it will be easily get-at-able when wanted.

This done the sailors return to the tug and Engineer Serko signs to me to go below.

A short iron ladder leads into a central cabin where various bales and packages are stored, and for which no doubt there was not room in the hold of the schooner. I am pushed into a side cabin, the door is shut upon me, and here I am once more a prisoner in profound darkness.

I recognize the cabin the moment I enter it. It is the place in which I spent so many long hours after our abduction from Healthful House, and in which I was confined until well out at sea off Pamlico Sound.

It is evident that Thomas Roch has been placed in a similar compartment.

A loud noise is heard, the banging of the lid as it closes, and the tug begins to sink as the water is admitted to the tanks.

This movement is succeeded by another--a movement that impels the boat through the water.

Three minutes later it stops, and I feel that we are rising to the surface again.

Another noise made by the lid being raised.

The door of my cabin opens, and I rush out and clamber on to the platform.

I look around and find that the tug has penetrated to the interior of Back Cup mountain.

This is the mysterious retreat where Count d'Artigas lives with his companions--out of the world, so to speak.

CHAPTER IX.

INSIDE BACK CUP.

The next morning I am able to make a first inspection of the vast cavern of Back Cup. No one seeks to prevent me.

What a night I have pa.s.sed! What strange visions I have seen! With what impatience I waited for morning!

I was conducted to a grotto about a hundred paces from the edge of the lake where the tug stopped. The grotto, twelve feet by ten, was lighted by an incandescent lamp, and fitted with an entrance door that was closed upon me.

I am not surprised that electricity is employed in lighting the interior of the cavern, as it is also used in the submarine boat. But where is it generated? Where does it come from? Is there a manufactory installed somewhere or other in this vast crypt, with machinery, dynamos and acc.u.mulators?

My cell is neatly furnished with a table on which provisions are spread, a bunk with bedding, a basket chair, a wash-hand-stand with toilet set, and a closet containing linen and various suits of clothes. In a drawer of the table I find paper, ink and pens.

My dinner consists of fresh fish, preserved meat, bread of excellent quality, ale and whisky; but I am so excited that I scarcely touch it.

Yet I feel that I ought to fortify myself and recover my calmness of mind. I must and will solve the mystery surrounding the handful of men who burrow in the bowels of this island.

So it is under the carapace of Back Cup that Count d'Artigas has established himself! This cavity, the existence of which is not even suspected, is his home when he is not sailing in the _Ebba_ along the coasts of the new world or the old. This is the unknown retreat he has discovered, to which access is obtained by a submarine pa.s.sage twelve or fifteen feet below the surface of the ocean.

Why has he severed himself from the world? What has been his past?

If, as I suspect, this name of d'Artigas and this t.i.tle of Count are a.s.sumed, what motive has he for hiding his ident.i.ty? Has he been banished, is he an outcast of society that he should have selected this place above all others? Am I not in the power of an evildoer anxious to ensure impunity for his crimes and to defy the law by seeking refuge in this undiscoverable burrow? I have the right of supposing anything in the case of this suspicious foreigner, and I exercise it.

Then the question to which I have never been able to suggest a satisfactory answer once more surges into my mind. Why was Thomas Roch abducted from Healthful House in the manner already fully described?

Does the Count d'Artigas hope to force from him the secret of his fulgurator with a view to utilizing it for the defence of Back Cup in case his retreat should by chance be discovered? Hardly. It would be easy enough to starve the gang out of Back Cup, by preventing the tug from supplying them with provisions. On the other hand, the schooner could never break through the investing lines, and if she did her description would be known in every port. In this event, of what possible use would Thomas Roch's invention be to the Count d'Artigas Decidedly, I cannot understand it!

About seven o'clock in the morning I jump out of bed. If I am a prisoner in the cavern I am at least not imprisoned in my grotto cell.

The door yields when I turn the handle and push against it, and I walk out.