Within another day, we were close over it. Of necessity our velocity was much less now. We had tilted so that the asteroid was under us, with our base gravity plates in negation. Zura for twenty-four earth-hours had been repulsing us, retarding us, as we dropped upon it. Dr. Livingston had made careful calculations. The total mass of Zura, small as the asteroid was in size, he had figured to be nearly that of the earth. We confirmed it now, by the repulsing effect it had upon us. Gradually we slowed, poised now midway in the northern hemisphere, Zura had a rotation on its axis of almost exactly four hours. That we had been able to check now--there had been six rotations in the span of an earth-day, as measured by our chronometer. A thousand miles up? It seemed now that we were no more than that. The Benson curve-rays, here in the turret, showed us on our tilted mirrors the full image of the little world directly under us. Its convexity long since had been apparent. It spread now like a huge cloud-enveloped ball, covering almost all the lower firmament. "The clouds are lessening," Dr. Livingston said, as again he and I were alone in the turret. "We'll be able to descend easily through this atmosphere." "Yes," I agreed. There had been faint, though unmistakable, evidences of Xalite in many places. We had decided that our best course was to descend before the storms came back. Most of the moisture-masses seemed clustered over the southern hemisphere now. Here in the north, for six Zurian days it had been fairly clear. Swift alternation of day and night--days of gray, hazy light, with the sunlight often striking through. And nights of glittering stars. We had seen all the surface of the northern hemisphere now. Everywhere it was the same--bleak, metallic-looking gray rocks, wildly tumbled; huge, fantastic ice and snow formations; strewn pools of water, choked with melting ice. Alan and I had mentioned that weird vision we had had of a living girl, so strangely fashioned in human mold. Was she real--or had our fancy tricked us? Dr. Livingston had blankly stared. From the big, handsome Peter Duroh had come a laugh and a ribald expression of hope that we were right. James Carruthers had merely stared incredulously, with his thin lips smiling and a look in his alert eyes that somehow seemed predatory. But whether we had seen something animal or human, assuredly it had been alive. This atmosphere then, doubtless would be breatheable to us; and the temperature down there, by daylight at least, must be around 40F. Dr. Livingston was checking his instruments. Another hour had passed. "Only five hundred miles of altitude now," he said. "I think we may use a little less repulsion for a time, and then the final retardation must begin."