"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 pa.s.sed me, on his way to his laboratory."

"G.o.d 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 acc.u.mulators 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 acc.u.mulators 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 impa.s.sibility--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 ma.s.s 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 sh.o.r.e, 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.