It was an hour before they all stood together at the top of the break, and here MacDonald swung sharply to the right, and came soon to the rock-strewn bed of a dried-up stream that in ages past had been a wide and rushing torrent.

Steadily, as they progressed down this, the rumble and roar grew nearer.

It seemed that it was almost under their feet, when again MacDonald turned, and a quarter of an hour later they found themselves at the edge of a small plain; and now all about them were cold and towering mountains that shut out the sun, and a hundred yards to their right was a great dark cleft in the floor of the plain, and up out of this came the rumble and roar that was like the sullen anger of monster beasts imprisoned deep down in the bowels of the earth.
MacDonald got off his horse, and Aldous and Joanne rode up to him.

In the old man's face was a look of joy and triumph.
"It weren't so far as I thought it was, Johnny!" he cried.

"Oh, it must ha' been a turrible night--a turrible night when Jane an' I come this way! It took us twenty hours, Johnny!" "We are near the cavern ?" breathed Joanne.
"It ain't more'n half a mile farther on, I guess.