We groped our way about seventy-five feet, which was as far as we could make out the opening distinctly, and sat down to wait.  I still had the rest of the tailor-made cigarettes, which I shared with Tim.  We did not talk, for we wished to listen for sounds outside.  To judge by her breathing, I think Miss Emory dozed, or even went to sleep.

About an hour later I thought to hear a single tinkle of shale.  Tim heard it, too, for he nudged me.  Our straining ears caught nothing further, however; and I, for one, had relaxed from my tension when the square of light was darkened by a figure.  I was nearest, so I raised Cortinez’s gun and fired.  The girl uttered a scream, and the figure disappeared.  I don’t know yet whether I hit him or not; we never found any blood.

We made Miss Emory lie down behind a little slide of rock, and disposed ourselves under shelter.

“We can take them as fast as they come,” exulted Tim.

“I don’t believe there are more than two or three of them,” I observed.  “It would be only a scouting party.  They will go for help.”

As there was no longer reason for concealment, we talked aloud and freely.

Now ensued a long waiting interim.  We could hear various sounds outside as of moving to and fro.  The enemy had likewise no reason for further concealment.

“Look!” suddenly cried Tim.  “Something crawling.”

He raised the 30-30 and fired.  Before the flash and the fumes had blinded me I, too, had seen indistinctly something low and prone gliding around the corner of the entrance.  That was all we could make out of it, for as you can imagine the light was almost non-existent.  The thing glided steadily, untouched or unmindful of the shots we threw at it.  When it came to the first of the crazy uprights supporting the roof timbers it seemed to hesitate gropingly.  Then it drew slowly back a foot or so, and darted forward.  The ensuing thud enlightened us.  The thing was one of the long, squared timbers we had noted outside; and it was being used as a battering ram.

“They’ll bring the whole mountain down on us!” cried Tim, springing forward.

But even as he spoke, and before he had moved two feet, that catastrophe seemed at least to have begun.  The prop gave way:  the light at the entrance was at once blotted out; the air was filled with terrifying roaring echoes.  There followed a succession of crashes, the rolling of rocks over each other, the grinding slide of avalanches great and small.  We could scarcely breathe for the dust.  Our danger was that now the thing was started it would not stop:  that the antique and inadequate supports would all give way, one bringing down the other in succession until we were buried.  Would the forces of equilibrium establish themselves through the successive slight resistances of these rotted, worm-eaten old timbers before the constricted space in which we crouched should be entirely eaten away?