"But how could they have lived?"
"We will talk that over, Bertie, if we find any of them there. Now we must turn back. It is not more than a mile at the outside to the place where we can climb the hillside. In that way we shall be able to look down into this ravine, and take a general view of the place. We shall know what we are doing then, whereas if we were to go on through the gorge without knowing anything about it, we might find ourselves caught in a trap. It won't make half an hour's difference, for the ground up there will be as good walking as it is here, while we might find all sorts of obstacles in this ravine, and with two guns apiece, ammunition, pistols, coils of rope, food, and so on, we should find it awkward work climbing among heaps of rocks.
"You were saying, How could a group of people exist here for centuries without any communication with the outside world? Well, I don't suppose they could. They might get water from the stream, and possibly there may be some way of getting down to the sea-shore; anyhow, this stream must find a passage when it is in flood. They might have been able to get enough fish for their wants; but a fish-and-water diet would scarcely be sufficient.
"At the same time we are by no means sure that they could have had no communication with the outside, for just as some families may have been ordered to live here, others may have been instructed to supply them with food. The watchers may have had a store of gold-dust sufficient to last them all this time, and their friends outside may have brought them a sheep or two, and corn and other articles of necessity once a week. There could have been no difficulty in doing so. The stories of demons, and probably the murder of inquisitive people who tried to pry into what was going on, created such a dread of the place that those in the secret would come and go without the slightest difficulty. Conceivably, young men may from time to time have gone out for a year into the world and brought back wives with them, or girls may have been sent by the people in league with them outside, and obtained husbands, which is less likely. I should think it was more probable that young boys and girls would be kidnapped, and brought in here from time to time. All this is pure guesswork, of course, but nevertheless there may be people here, and it is just as well to take a look round from above before we trust ourselves inside the place."
On gaining the plateau they followed the crest of the valley until they came to a spot where the ravine appeared to end. They found that in fact it made a sharp turn. It was here only some ten feet wide, but soon broadened out to thirty. Fifty yards farther there was another sharp bend, the ravine narrowed to twenty feet, and the sides became absolutely perpendicular. Twenty yards farther still they saw something like a wall about thirty or forty feet high stretching across the gorge, which was here some seventy feet deep. About twenty feet from the foot there was a steep ascent of rocks, such as might have fallen there by a slip from one side or the other. Above these a perpendicular wall rose for another twenty-five feet. Harry and his brother looked at it in surprise from the height at which they stood. Its appearance was precisely that of the wall-precipices on each side. It was rough and uneven, and they could see no signs of any joints.
"It looks as if it were natural," Bertie said, "but it can't be."
"No, it must certainly be artificial, but it is a wonderful imitation, and certainly anyone coming up the ravine would suppose that bank of rocks at the foot had fallen from its face; but we know that it can't be that, for the water makes its way through. Besides, you see it is only three feet wide at the top, and then there is a narrow ledge a couple of feet wide, which was evidently made for the garrison to stand upon and shoot their arrows at anyone attempting to come up the ravine. Behind the slope is all rough rocks, except just below our feet, where there is a narrow stone staircase of regularly-cut steps. It is so narrow that it could not be noticed by anyone standing here, unless they bent over to look straight down as I am doing. Well, it is just as well that we made the circuit, for we certainly could not have climbed over there."
Another sharp turn, and the ravine ran straight towards the castle. They hurried on, and when they had gone fifty yards stood at the edge of a roughly circular pit. It was seventy or eighty feet across, narrowing at each end. At one end was the ravine at whose mouth they were standing, and directly opposite, in what might be called the neck of the bottle, stood the Castle of the Demons. It was some fifty feet in width, and as it stood back about forty feet up the neck it could hardly be seen at any point except that at which they were standing. There was no door or other opening at less than some twenty-five feet from the ground. At that height was a broad aperture about four feet high and twelve wide. Above this were several smaller openings about four feet square. The singular point in the structure was a rough arch of rock, which extended above it and formed its roof. This arch projected thirty or forty feet in front of the building, so that the latter had the appearance of standing in a great cave.
"What an extraordinary-looking place!" Bertie said in a low voice.
"Extraordinary, but how splendidly chosen for concealment! You see the top of the rock above it is level with the ground on either side. This would perfectly well account for people riding along the line of the cliffs, and passing over without dreaming that there was a house below them. Even if they went to the edge on this side, they would simply see this deep pit and the ravine beyond, but could not by any possibility obtain a sight of the house unless they came round to nearly where we are standing, which they could have no possible motive for doing. Besides, you see, all the way we have been passing through a thick bush; and I have no doubt that in the old time a wood stood here, possibly planted by the builders of the house. Of course the arch existed before the house was built. The stratum below was probably softer, and the stream gradually trickled through, and perhaps in some great flood, when this basin was full, burst its way out, after which the rock gradually fell until it formed that great natural arch."