enly I heard a sound that I understood too well--the curious,
rattling sound of a man who is trying to call out when he is being
strangled.

"Harry!" I cried, and I fought like a wild man to get to him, with
knife, feet, hands, teeth. I reached his coat, his arm; it was
dangerous to strike so near him in the dark, but I felt him sinking to
the ground.

Then I found the taut, straining fingers about his throat, and lunged
forward with the knife--and the fingers relaxed.

Again we were fighting together side by side.

As their bodies fell in front of us we were pressed harder, for those
behind climbed up on the corpses of their fellows and literally
descended on our heads from the air. We could not have held out much
longer; our breath was coming in quick, painful gasps; Harry stumbled
on one of the prostrate brutes and fell; I tried to lift him and was
unequal to the task.

It appeared to be the end.

Suddenly there rang throughout the cavern a sound as of a gigantic,
deep-toned bell. The walls sent it back and forth with deafening
echoes; it was as though the mountain had descended with one tremendous
crash into its own bowels.

As though by magic, the assault ceased.

The effect was indescribable. We could see nothing; we merely became
suddenly aware that there were no longer hands clutching at our throats
or hairy bodies crushing us to the ground. It was as though the horde
of unseen devils had melted into thin air. There were movements on the
ground, for many of them had been wounded; a man cannot always reach
the spot in the dark. This lasted for two or three minutes; they were
evidently removing those who still had life in them, for the straining
breath of men dragging or lifting burdens was plainly audible.

Gradually that, too, died away with the last reverberations of the
mysterious sound that had saved us, and we found ourselves alone--or at
least unmolested--for in the darkness we could see nothing, except the
dim outlines of the prostrate forms at our feet.

The cavern was a shambles. The smell was that of a slaughter-house. I
had had no idea of the desperateness of our defense until I essayed to
scramble over the heap of bodies to dry ground; I shuddered and grew
faint, and Harry was in no better case.

Worse, he had dropped his knife when we stumbled, and we were forced to
grope round in that unspeakable mess for many minutes before we found
it.

"Are you hurt, lad?" I asked when on