“Hastily concealing my bundle, I slipped into some dense undergrowth by the entrance to the cave, and crouched there, waiting and watching.  I had not waited very long before a yellow-robed mendicant passed by, carrying a bundle not unlike my own, whereby I concluded that he had come some distance.  There was nothing remarkable in his appearance except the fact of his travelling during the hottest part of the day.  Therefore I did not doubt that he was one of the members of the secret organization and was bound for headquarters.

“I gave him half an hour’s start and then resumed my march.  If he could travel beneath a noonday sun, so could I.

“In this fashion I presently came out upon a larger and higher plateau, carpeted with a uniform, stunted undergrowth, and extending, as flat as a table, to the very edge of a sheer precipice, which rose from it to a height of three or four hundred feet—­gnarled, naked rock, showing no vestige of vegetation.

“By this time the sound of falling water had become very loud, and as I emerged from the gorge through which the path ran on to this plateau I saw, on the further side of this tableland, the yellow robe of the mendicant.  He was walking straight for the face of the precipice, and straight for the spot at which, from a fissure in the rock, a little stream leapt out, to fall sheerly ten or fifteen feet into a winding channel, along which it bubbled away westward, doubtless to form a greater waterfall beyond.

“The mendicant was fully half a mile away from me, but in that clear tropical air was plainly visible; and, fearing that he might look around, I stepped back into the comparative shadow of the gorge and watched.

“Gentlemen, I saw a strange thing.  Placing his bundle upon his head, he walked squarely into the face of the waterfall and disappeared!”

CHAPTER XXXII.  STORY OF THE CITY OF FIRE (CONTINUED)

“‘Quitting air, must pass through water.’  The meaning of those words became apparent enough.  I stood at the foot of the waterfall, looking up at the fissure from which it issued.

“Although the fact had been most artistically disguised, I could not doubt that this fissure was artificial.  A tunnel had been hewn through the rock, and a mountain stream diverted into it.  Indeed, on close inspection, I saw that it was little more than a thin curtain of water, partly concealing what looked like the entrance of a cave.

“A great deal of mist arose from it.  But I could see that, beyond a ducking, I had little to fear; and, stepping down into the bed of the little stream which frothed and bubbled pleasantly about my bare legs, I set my bundle on my head as the mendicant had done, and plunged through the waterfall, into a place of delicious coolness.

“A strange greenish light prevailed here and directly before me I saw a flight of stone steps leading upward through a tunnel in the rock.  By the light of a pocket torch with which I had provided myself, I began to ascend the steps.  These, as I have said, were hewn out of the solid rock, and as they numbered something like seven hundred, the labour expended upon the making of this extraordinary staircase must have been stupendous.