"Then any substance producing life and modified by it could--if you go far enough back--be the product of a machine. But it would have taken so long to produce life that the original matter, that bore the direct imprint of the machine, would have disappeared." "An error," said Creno desperately. "There is just this case." "By the time these creatures have arrived at self-knowledge the machine will be gone. They will not know it ever existed, and--" "That is all it means. There is just this one case. Now we must leave this unimportant example of minor dimensions!" He strained consciousness to a forward movement but Harta remained behind. He had to pull back. "Start," he ordered. Her mind's obstinately frozen stance made him freeze too. He applied all his force to bring her back into control, but she still held fast. "Something more is hidden from me. I will be back," she said. And she disappeared from the ridge. He had never faced such a quandary before on a training trip with a younger one. If he went in pursuit he would find her ultimately--that was in the nature of being older and wiser--but, if she revolted against his pursuit, she could extend the time considerably on this forsaken planet. And he wanted to get her away as soon as possible. The more time here the more chance that the awful truth would come to her before her time. He watched the growing waves of creatures floundering toward the vast oozing puddle, which refilled itself as quickly as it was diminished by them, and the receding waves of those that had already fed. This, he could see, was an endless process. The whole life of the species moved in continuous systole-diastole around the machine. Soon he would have to go in search of her. But then she was back at his side, her being for this world once more solidified. She concentrated for a moment on the pink-striped waves of rippling inward and outward around the great sustaining pool, then communicated with him. "We can leave now. There is nothing more to see." Something in her mind remained closed to his, as the mind of younger never should be to older. But at least he could see with relief that the worst had not happened. The deeper knowledge had not arrived to her too early when it could only hurt. All he found turned to him--as they receded from this thin-manifold universe, then moved up the dimension ladder to their home level--was a surface of happiness. Suddenly, though, as they prepared for flight in that hyperspace all her joy was gone.