Hardwick frowned to himself. The bolster-truck more or less flowed up the crumbling, inexplicably drawing-back mass of soil. Atop it, things looked almost normal. Almost. There was a highway leading away from the cliff. At first glance it seemed perfect. But it was cracked down the middle for a hundred yards, and then the crack meandered off to the side and was gone. There was a great tree, which leaned drunkenly. A mile along the roadway its surface buckled as if something had pressed irresistibly upward from below. The truck rolled over the break. It was notable that the motion of the truck was utterly smooth. It made no vibration at all. But even so it slowed before it moved through a place where houses--dwellings and a shop or two--clustered closely together on each side of the road. There were people in and about the houses, but they were doing nothing at all. Some of them stared hostilely at the Survey truck. Some others deliberately turned their backs to it. There were vehicles out of shelter and ready to be used, but none was moving. All--very oddly--were pointed in the direction from which the bolster-truck had come. The truck went on. Presently the extraordinary flatness of the landscape became apparent. It was possible to see a seemingly illimitable distance. The ocean forty miles away showed as a thread of blue beneath the horizon. The island was an almost perfectly plane surface. But the windward side was tilted up to a height of four thousand feet above the sea, and the downwind side slipped gently beneath the waves. There was no hill visible anywhere. No mountains. No valleys save the extremely minor gullies worn by rain. Even they had been filled in, or dammed, and tied in to irrigation systems. There was a place where there was a row of trees along such a water-course. Half the row was fallen, and a part of the rest was tilted. The remainder stood upright and firm. All the vegetation was perfectly familiar. Most colonies have some vegetation, at least, directly descended from the mother planet Earth. But this island on Canna III had been above-water perhaps no more than three or four thousand years. There had been no time for local vegetation to develop. When the Survey took it over, there was only tidal seaweed, only one variety of which had been able to extend itself in web-like fashion over the soil above water. Terrestrial plants had wiped it out, and everything was green, and everything was human-introduced. But there was something wrong with the ground. At this place the top of the soil bulged, and tall corn-plants grew extravagantly in different directions. There, there was a narrow, lipless gap in the ground's surface. An irrigation-ditch poured water into it. It was not filled. * * * * * Barnes said distressedly: "Excuse me, sir, but how the devil did this happen?"