Harg-Ofortu frowned impatiently, fingered his subject's pulse, and snapped off a switch. He motioned to his assistant. "The woman," he said, "has fainted. Take her away. We will continue our experiments later." * * * * * When Sandra wakened at last, it was to find Larry bending over her, chafing her wrists, looking down into her eyes anxiously. There was a lingering warmth on her lips; short seconds ago might have found his face even closer to hers. He sighed with relief as her eyes opened. The sigh became an oath. "Damn his rotten little hide! I thought you were out for keeps. What did he do, Sandy? Are you all right?" She was all right. A little rocky. She discovered that when she tried to rise and her head ached wickedly. But she was all right. She told him her memories of the experiment. "It was like a horrible dream, Larry. But it was more than a dream. It was true. I have lived those scenes before ... somewhere ... sometime. They were so clear, so vivid." She shuddered. "But I hate to think of going through that again. I won't be able to stand it. I could feel my brain tottering on the brink of insanity toward the end." Larry said savagely, "You won't have to go through it again!" Sandra touched his hand, smiling wanly. "It's no use pretending, Larry. We're caught in a trap, you and I. Fate has destroyed us; thrust us forward into a Time when man is without mercy. Humanity is dead. All that remains is a race of grinning, scientific demons." "That," interrupted Larry feverishly, "is where you're wrong, youngster! I haven't been sitting around twiddling my thumbs while you were gone. I've had a visitor." "A--a visitor?" Larry told her, then, of the silver-haired giant who had forced entrance into the cell. "His name was Sert. He was a man and a friend. He was one of the Underlings." "The Underlings?" repeated Sandra. "Yes. This world we are in is not peopled only by cold-blooded creatures like Harg. There are two mutant races of humanity. One tall and strong, as we always dreamed the future-man might be; the other spindling, puny, and viciously intelligent. "These latter, Harg and his fellows, are the descendants of those men whose brains, for some reason more receptive to the stimulus of ultra-short wave radiation, were spurred to great heights during the period of the Great Catastrophe. "The cosmic bombardment had three types of result. Either it killed outright--and Sert tells me that millions died--or it damaged the brain and did not harm the body, or it impaired the physique and stimulated the brain. During the era of chaos which preceded the building of the _impervite_ domes, the highly activated dwarfs seized the reins of leadership. They have held them ever since. The Underlings are their workers, their slaves, their servants." Sandra said despairingly, "But I don't see how it can profit us to join forces with dull-witted slaves--"