sixty. Nine eighty. Nine ninety—that's from the bottom edge near the spine that's being surrounded. Nine eighty-five—" The voice droned on until about two dozen readings had been taped. Then, "I'm going closer now. The sampler is just a ladle on a twelve-foot handle we improvised, so I'll have to get that close. The stuff is moving slowly; there should be no trouble. I'm in reach now. The lava is very liquid; there's no trouble getting the sampler in—or out again—it's not very dense, either. I'm heading back toward the tractor now. No, Ren, don't come to meet me." There was a minute of silence, while Zaino pictured the spacesuited figure with its awkwardly long burden, walking away from the creeping menace to the relative safety of the tractor. "It's frozen solid already; we needn't worry about spilling. The temperature is about—five eighty. Give me the markers, please." Another pause, shorter this time. Zaino wondered how much of that could be laid to a faster walk without the ladle and how much to the lessening distance between flow and tractor. "I'm tossing the first marker close to the edge—it's landed less than a foot from the lava. They're all on a light cord at ten-foot intervals; I'm paying out the cord as I go back to the tractor. Now we'll stand by and time the arrival at each marker as well as we can." "How close are you to the main cone?" asked Zaino. "Not close enough to see its base, I'm afraid. Or to get a sample of it, which is worse. We—goodness, what was that?" Zaino had just time to ask, "What was what?" when he found out. IV For a moment, he thought that the Albireo had been flung bodily into the air. Then he decided that the great metal pillar had merely fallen over. Finally he realized that the ship was still erect, but the ground under it had just tried to leave. Everyone in the group had become so used to the almost perpetual ground tremors that they had ceased to notice them; but this one demanded attention. Rowson, using language which suggested that his career might not have been completely free of adventure after all, flashed through the communication level on his way down to the power section. Schlossberg and Babineau followed, the medic pausing to ask