n
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.

"The tug! The tug!" I exclaimed. "Lieutenant, here is the tug
returning to Back Cup!"

"Full speed astern," ordered the officer, and the _Sword_ drew back
just as she was about to enter the tunnel.

One chance remained. The lieutenant had swiftly turned off the light,
and it was just possible that we had not been seen by the people in
the tug. Perhaps, in the dark waters of the lagoon, we should escape
notice, and when the oncoming boat had risen and moored to the jetty,
we should be able to slip out unperceived.

We had backed close in to the south side and the _Sword_ was about to
stop, but alas, for our hopes! Captain Spade had seen that another
submarine boat was about to issue through the tunnel, and he was
making preparations to chase us. How could a frail craft like the
_Sword_ defend itself against the attacks of Ker Karraje's powerful
machine?

Lieutenant Davon turned to me and said: "Go back to the compartment
where Thomas Roch is and shut yourself in. I will close the
after-door. There is just a chance that if the tug rams us the
water-tight compartments will keep us up."

After shaking hands with the lieutenant, who was as cool as though we
were in no danger, I went forward and rejoined Thomas Roch. I closed
the door and awaited the issue in profound darkness.

Then I could feel the desperate efforts made by the _Sword_ to
escape from or ram her enemy. I could feel her rushing, gyrating and
plunging. Now she would twist to avoid a collision. Now she would rise
to the surface, then sink to the bottom of the lagoon. Can any one
conceive such a struggle as that in which, like two marine monsters,
these machines were engaged in beneath the troubled waters of this
inland