“The greatest monolith in all the world,” muttered Orme, “and Higgs is dead. Oh! if only he had lived to see it, he would have gone happy. I wish it had been I who was taken; I wish it had been I!” and he wrung his hands, for it is the nature of Oliver Orme always to think of others before himself.

“That’s what we have come to blow up,” soliloquized Quick. “Well, those ‘azure stinging-bees,’ or whatever they call the stuff (he meant azo-imides) are pretty active, but it will take a lot of stirring if ever we get there. Seems a pity, too, for the old pussy is handsome in his way.”

“Come down,” said Orme. “We must find out where we are; perhaps we can escape in the mist.”

“One moment,” I answered. “Do you see that?” and I pointed to a needle-like rock that pierced the fog about a mile to the south of the idol valley, and say two miles from where we were. “That’s the White Rock; it isn’t white really, but the vultures roost on it and make it look so. I have never seen it before, for I passed it in the night, but I know that it marks the beginning of the cleft which runs up to Mur; you remember, Shadrach told us so. Well, if we can get to that White Rock we have a chance of life.”

Orme studied it hurriedly and repeated, “Come down; we may be seen up here.”

We descended and began our investigations in feverish haste. This was the sum of them: In the arch under the tower were set two great doors covered with plates of copper or bronze beaten into curious shapes to represent animals and men, and apparently very ancient. These huge doors had grilles in them through which their defenders could peep out or shoot arrows. What seemed more important to us, however, was that they lacked locks, being secured only by thick bronze bolts and bars such as we could undo.

“Let’s clear out before the mist lifts,” said Orme. “With luck we may get to the pass.”

We assented, and I ran to the camels that lay resting just outside the arch. Before I reached them, however, Quick called me back.

“Look through there, Doctor,” he said, pointing to one of the peep-holes.

I did so, and in the dense mist saw a body of horsemen advancing toward the door.