We reached the corridor's end, sprang out of our machine and through the door into the well-like bottom of the shaft. At once the plant-man was clambering up the peg-ladder, followed by the Arcturian with myself last. Up, up we climbed, putting all our strength into the effort, for we knew that not many minutes remained for action. Then suddenly as I looked down I stopped and breathed an exclamation; for standing at the bottom of the shaft were two of the nebula-creatures, not more than a hundred feet below us--two white masses of flesh that were staring up toward us. A moment we hung motionless on the pegs, while the two weird beings gazed up, and then we saw one of them glide back into the corridor, racing back to the great caverns to sound the alarm, we knew. The other gazed up at us once more and then, to our horror, began to climb swiftly up after us. * * * * * I think now that of all that befell us there in the nebula world the moments that followed were the most agonizing. Swinging ourselves up by sheer muscular power, from peg to peg, we clambered up that giddy ladder, through a darkness impossible of description. Somewhere in that darkness below me, I knew, the nebula-creature that pursued us was swinging up after me, and I knew that to such a creature the negotiating of this dizzy ladder was child's play. Yet, spurred on by deadly fear, I struggled upward with superhuman speed, a hundred feet, another hundred, until a hope flashed across my brain that the thing that pursued us might have given up that pursuit. Then above us I glimpsed a little dot of glowing light, knew it for the shaft's mouth far above. And at the same moment that I glimpsed it, I felt a tug on my ankles, a powerful arm fasten round my body, and knew that the pursuing creature had reached me. I cried out involuntarily as I felt my feet twitched off the pegs on which they had rested, and dangled for a moment there by my hands while the creature below me tightened his grip on my feet and began to pull me steadily downward. All his force he must have put into that effort, and I felt my hands slipping on the peg which they held, knew that once I lost my hand-grip the creature below would release my feet also and send me hurtling down to death on the shaft's floor far below. In a deathly silence I hung there, striving against that deadly pull, and then felt one of my hands torn from its grip, felt the fingers of the other slipping on the peg they held, felt my will relaxing----