Making sure that all the Bree’s crew had returned aboard, he restarted the tank and resumed the eastward journey. The hills grew higher in the next few days, and twice they crossed streams of methane, fortunately so narrow that the sled could actually bridge them. It was well that the rise in the hills was gradual, for there was a little uneasiness among the sailors whenever they had to look down any distance; but that, Barlennan reported, was gradually decreasing.
And then, some twenty days after the start of the second lap of the journey, their minds were taken completely off the terrors of height by something which seized and froze the attention of every living being on both vehicles.
VII: STONE DEFENSE
Up to this time, most of the hills had been gentle, smooth slopes, their irregularities long since worn off by weather. There had been no sign of the holes and crevasses which Lackland somewhat feared before starting. The hilltops had been smoothly rounded, so that even had their speed been much higher the crossing of one would hardly have been noticed. Now, however, as they topped such an acclivity and the landscape ahead came into view a difference in the next hill caught every eye at once.
It was longer than most they had crossed, more a ridge across their path than a mound; but the great difference was in the top. Instead of the smooth, wind-worn curve presented by its fellows, it seemed at first glance actually jagged; a closer look showed that it was crowned with a row of boulders spaced with regularity that could only mean intelligent arrangement. The rocks ranged from monstrous things as big as Lackland’s tank down to fragments of basketball size; and all, while rough in detail, were generally spherical in shape. Lackland brought his vehicle to an instant halt and seized his glasses — he was in partial armor, but was not wearing the helmet. Barlennan, forgetting the presence of his crew, made a leap over the twenty yards separating the Bree from the tank and settled firmly on top of the latter. A radio had been fastened there for his convenience long before, and he was talking almost before he had landed.
„What is it, Charles? Is that a city, such as you were telling me about on your own world? It doesn’t look very much like your pictures.”
„I was hoping you could tell me,” was the answer. „It certainly is not a city, and the stones are too far apart for the most part to be any sort of wall or fort that I could imagine. Can you see anything moving around them? I can’t with these glasses, but I don’t know how keen your eyesight is.”
„I can just see that the hilltop is irregular; if the things on top are loose stones, I’ll have to take your word for it until we’re closer. Certainly I can see nothing moving. Anything my size would be impossible to see at that distance anyway, I should think.”
„I could see you at that range without these glasses, but I couldn’t count your eyes or arms. With them I can say pretty certainly that that hilltop is deserted. Just the same, I’ll practically guarantee that those stones didn’t get there by accident; we’d better keep eyes open for whoever set them up. Better warn your crew.” Lackland mentally noted the fact of Barlennan’s poorer eyesight; he was not physicist enough to have predicted it from the size of the native’s eyes.
For two or three minutes, while the sun moved far enough to reveal most of the areas* previously in shadow, they waited and watched; but nothing except the shadows moved, and finally Lackland started ‘the tank once more. The sun set while they were descending the slope. The tank had only one searchlight, which Lackland kept aiming at the ground in his path; so they could not see what, if anything, went on among the stones above. Sunrise found them just crossing another brook, and tension mounted as they headed uphill once more. For a minute or two nothing was visible, as the sun was directly ahead of the travelers; then it rose far enough to permit clear forward vision. None of the eyes fastened on the hilltop could detect any change from its appearance of the night before. There was a vague impression, which Lackland found was shared by the Mesklinites, that there were now more stones; but since no one had attempted to make a count of them before, this could not be proved. There was still no visible motion.
It took five or six minutes to climb the hill at the tank’s five-mile speed, so the sun was definitely behind them when they reached the top. Lackland found that several of the gaps between the larger stones were wide enough for the tank and sled, and he angled toward one of these as he approached the crest of the ridge. He crunched over some of the smaller boulders, and for a moment Dondragmer, on the ship behind, thought one of them must have damaged the tank; for the machine came to an abrupt halt. Barlennan could be seen still on top of the vehicle, all his eyes fixed on the scene below him; the Flyer was not visible, of course, but after a moment the Bree’s mate decided that he, too, must be so interested in the valley beyond as to have forgotten about driving.
„Captain! What is it?” Dondragmer hurled the question even as he gestured the weapons crew to the flame tanks. The rest of the crew distributed themselves along the outer rafts, clubs, knives, and spears in readiness, without orders. For a long moment Barlennan gave no answer, and the mate was on the point of ordering a party overboard to cover the tank — he knew nothing of the nature of the jury-rigged quick-firer at Lackland’s disposal — when ‘his captain.turned, saw what was going on, and gave a reassuring gesture.
„It’s all right, I guess,” he said. „We can see no one moving, but it looks a little like a town. Just a moment and the Flyer will pull you forward so that you can see without going overboard.” He shifted back to English and made this request to Lackland, who’promptly complied. This action produced an abrupt change in the situation.
What Lackland had seen at first — and Barlennan less clearly — was a broad, shallow, bowllike valley entirely surrounded by hills of the type they were on. There should, Lackland felt, have been a lake at the bottom; there was no visible means of escape for rain or melted snow. Then he noticed that there was no snow on the inner slopes of the hills; their topography was bare. And strange topography it was.
It could not possibly have been natural. Starting a short distance below the ridges were broad, shallow channels. They were remarkably regular in arrangement; a cross section of the hills taken just below where they started would have suggested a very pretty series of ocean waves. As the channels led on downhill toward the center of the valley they grew narrower and deeper, as though designed to lead rain water toward a central reservoir. Unfortunately for this hypothesis, they did not all meet in the center — they did not even all reach it, though all got as far as the relatively level, small floor of the valley. More interesting than the channels themselves were the elevations separating them. These, naturally, also grew more pronounced as the channels grew deeper; on the upper half of the slopes they were smoothly rounded ridges, but as the eye followed them down their sides grew steeper until they attained a perpendicular junction with the channel floors. A few of these little walls extended almost to the center of the valley. They did not all point toward the same spot; there were gentle curves in their courses that gave them the appearance of the flanges of a centrifugal pump rather than the spokes of a wheel. Their tops were too narrow for a man to walk on.
Lackland judged that channels and separating walls alike were some fifteen or twenty feet wide where they broke off. The walls themselves, therefore, were quite thick enough to be lived in, especially for Mesklinites; and the existence of numerous openings scattered over their lower surfaces lent strength to the idea that they actually were dwellings. The glasses showed that those openings not directly at the bottoms of the walls had ramps leading up to them; and before he saw a single living thing, Lackland was sure he was examining a city. Apparently the inhabitants lived in the separating walls, and ‘had developed the entire structure in order to dispose of rain. Why they did not live on the outer slopes of the hills, if they wanted to avoid the liquid, was a question that did not occur to him.