Small lakes and ordinary rivers bothered the golop very little if at all. There was perhaps a slightly increased sparkling, a slight stiffening, a little darkening, some freezing and breaking off of solid blocks; but the thing's forward motion was not noticeably slowed down. It drank a fairly large river and a lake one mile wide by ten miles long while the two men watched. The golop made no attempt to climb either foot-hills or mountains. It leveled them. It ate into their bases at its own level; the undermined masses, small and large, collapsed into the foul, corrosive semi-liquid and were consumed. Nor was there much raising of the golop's level, even when the highest mountains were reached and miles-high masses of solid rock broke off and toppled. There was some raising, of course; but the stuff was fluid enough so that its slope was not apparent to the eye. * * * Then the _Pleiades_ went back, over the place where the city had been and on to what had once been an ocean beach. The original wave of degradation had reached that shore long since, had attacked its sands out into deep water, and there it had been stopped. The corrupt flood was now being reinforced, however, by an ever-rising tide of material that had once been mountains. And the slope, which had not been even noticeable at the mountains or over the plain, was here very evident. As the rapidly-flowing golop struck water, the water shivered, came to a weirdly unforgettable cold boil, and exploded into drops and streamers and jagged-edged chunks of something that was neither water nor land; or rock or soil or sand or Satan's unholy brew. Nevertheless, the water won. There was _so_ much of it! Each barrel of water that was destroyed was replaced instantly and enthusiastically; with no lowering of level or of pressure. And when water struck the golop, the golop also shivered violently, then sparkled even more violently, then stopped sparkling and turned dark, then froze solid. The frozen surface, however, was neither thick enough nor strong enough to form an effective wall. Again and again the wave of golop built up high enough to crack and to shatter that feeble wall; again and again golop and water met in ultimately furious, if insensate, battle. Inch by inch the ocean's shoreline was driven backward toward ocean's depths; but every inch the ocean lost was to its tactical advantage, since the advancing front was by now practically filled with hard, solid, dead blocks of its own substance which it could neither assimilate nor remove from the scene of conflict. Hence the wall grew ever thicker and solider; the advance became slower and slower.