uffice 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 ri