There were only two outlets from that cave - the way I had come, and the way the river came. The first was closed, the second a sheer staring impossibility. I had been into every niche and cranny, and there was no sign of a passage. I sat down on the floor and looked at the wall of water. It fell, as I have already explained, in a solid sheet, which made up the whole of the wall of the cave. Higher than the roof of the cave I could not see what happened, except that it must be the open air, for the sun was shining on it. The water was about three yards distant from the edge of the cave's floor, but it seemed to me that high up, level with the roof, this distance decreased to little more than a foot.
I could not see what the walls of the cave were like, but they looked smooth and difficult. Supposing I managed to climb up to the level of the roof close to the water, how on earth was I to get outside on to the wall of the ravine? I knew from my old days of rock-climbing what a complete obstacle the overhang of a cave is.
While I looked, however, I saw a thing which I had not noticed before. On the left side of the fall the water sluiced down in a sheet to the extreme edge of the cave, almost sprinkling the floor with water. But on the right side the force of water was obviously weaker, and a little short of the level of the cave roof there was a spike of rock which slightly broke the fall. The spike was covered, but the covering was shallow, for the current flowed from it in a rose-shaped spray. If a man could get to that spike and could get a foot on it without being swept down, it might be possible - just possible - to do something with the wall of the chasm above the cave. Of course I knew nothing about the nature of that wall. It might be as smooth as a polished pillar.
The result of these cogitations was that I decided to prospect the right wall of the cave close to the waterfall. But first I went rummaging in the back part to see if I could find anything to assist me. In one corner there was a rude cupboard with some stone and metal vessels. Here, too, were the few domestic utensils of the dead Keeper. In another were several locked coffers on which I could make no impression. There were the treasure-chests too, but they held nothing save treasure, and gold and diamonds were no manner of use to me. Other odds and ends I found - spears, a few skins, and a broken and notched axe. I took the axe in case there might be cutting to do.
Then at the back of a bin my hand struck something which brought the blood to my face. It was a rope, an old one, but still in fair condition and forty or fifty feet long. I dragged it out into the light and straightened its kinks. With this something could be done, assuming I could cut my way to the level of the roof.
I began the climb in my bare feet, and at the beginning it was very bad. Except on the very edge of the abyss there was scarcely a handhold. Possibly in floods the waters may have swept the wall in a curve, smoothing down the inner part and leaving the outer to its natural roughness. There was one place where I had to hang on by a very narrow crack while I scraped with the axe a hollow for my right foot. And then about twelve feet from the ground I struck the first of the iron pegs.
To this day I cannot think what these pegs were for. They were old square-headed things which had seen the wear of centuries. They cannot have been meant to assist a climber, for the dwellers of the cave had clearly never contemplated this means of egress. Perhaps they had been used for some kind of ceremonial curtain in a dim past. They were rusty and frail, and one of them came away in my hand, but for all that they marvellously assisted my ascent.
I had been climbing slowly, doggedly and carefully, my mind wholly occupied with the task; and almost before I knew I found my head close under the roof of the cave. It was necessary now to move towards the river, and the task seemed impossible. I could see no footholds, save two frail pegs, and in the corner between the wall and the roof was a rough arch too wide for my body to jam itself in. Just below the level of the roof - say two feet - I saw the submerged spike of rock.
The waters raged around it, and could not have been more than an inch deep on the top. If I could only get my foot on that I believed I could avoid being swept down, and stand up and reach for the wall above the cave.
But how to get to it? It was no good delaying, for my frail holds might give at any moment. In any case I would have the moral security of the rope, so I passed it through a fairly staunch pin close to the roof, which had an upward tilt that almost made a ring of it. One end of the rope was round my body, the other was loose in my hand, and I paid it out as I moved. Moral support is something. Very gingerly I crawled like a fly along the wall, my fingers now clutching at a tiny knob, now clawing at a crack which did little more than hold my nails. It was all hopeless insanity, and yet somehow I did it. The rope and the nearness of the roof gave me confidence and balance.
Then the holds ceased altogether a couple of yards from the water. I saw my spike of rock a trifle below me. There was nothing for it but to risk all on a jump. I drew the rope out of the hitch, twined the slack round my waist, and leaped for the spike.
It was like throwing oneself on a line of spears. The solid wall of water hurled me back and down, but as I fell my arms closed on the spike. There I hung while my feet were towed outwards by the volume of the stream as if they had been dead leaves. I was half-stunned by the shock of the drip on my head, but I kept my wits, and presently got my face outside the falling sheet and breathed.
