I took a few steps toward it, and it disappeared immediately, as though alarmed—apparently into the heart of the mountain.
I thought, of course, that it was crouching in a hollow place, or behind a boulder, and would reappear on my approach, but when I reached the spot where it had been it was nowhere to be seen. And the pad-prints ran toward a tiny hole no bigger than the entrance to a fox's lair—and ended there.
At this spot an enormous boulder lay, almost concealing the burrow. I put my shoulder against it—in the hope of dislodging it sufficiently to enable me to see into the cavity. To my astonishment, at the first touch it rolled into a new position, disclosing a wide natural tunnel in the mountainside, through which a sleigh might have passed easily!
I saw at once the explanation. The boulder was a rocking stone. It must have fallen at some time from the top of the arch, and happened to be so poised that at a touch it could be swung into one of two positions, alternately disclosing and concealing the tunnel in the cliff wall.
I stepped within and, striking a match perceived that I was standing inside a vast cave—a vaulted chamber that ran apparently straight into the heart of the mountains.
Great stalactites hung from the roof and dripped water upon the floor, on which numerous small stalagmites were forming, where they had not been crumbled away by the passage and repassage of sleighs. These had left two well-defined tracks in the soft stone under my feet.
The cave was one of those common formations in limestone hills. How far it ran I could not know, but I had little doubt that at last I was well upon my approach to the château.
The interior was completely dark. At intervals I struck matches from the box which I had brought with me, but the road always ran clear and straight ahead, and I could even guide myself by the ruts in the ground.
And every time I struck a match I could see the vaulted cavern, wide as a great cathedral, extending right and left and in front of me.
I must have been journeying for half an hour when I perceived a faint light ahead of me, and at the same time I heard the gurgling of a torrent somewhere near at hand.