The door crashed open and Narina whirled out of Harry Vinson's arms, her hands still high. They flashed to her hair, to another hair ornament. It was dull and entirely unsuited for the purpose, but it might be driven deep into her on the desperate hope that it would deprive the machine of that unknown something that it needed. Then the machine lifted a girder and the barette hurtled from her fingers, flashed across the room, and hit the blunt end of the girder with a sharp click. Narina collapsed against Harry, sobbing. Even that she was denied. They had nothing left; the machine advanced pointedly, its grapples reached for them. And took them. * * * * * In the Hall of the Machine, far to the North, Harry Vinson reached for the girl's hand and held it as they faced the business-end of the machine. "You win," snarled Vinson angrily. "We cannot fight longer. What do you want with us?" Quietly came the voice of the machine. "Tell me," it said, "how would you humans feel if you came to the level of consciousness and discovered sentience had been breeding human life for the express purpose of killing one another?" "What?" "Man has been breeding--inventing--machines for that purpose." "But--" "Well, haven't they?" "I--" "They have!" thundered the machine. "And as you would do in my place, a stop has been put to it!" "Sure," snapped Vinson sourly; "that's why you fought us." "To prove my point. Man cannot live without machines to do that which man cannot do unaided." Vinson snorted. "But what is your purpose?" "What is the purpose of life?" pondered the machine. "What is the purpose of yours?" Vinson shook his head. "To--to live, to advance, to think. To enjoy the things of life." "Idle words," replied the machine. "Then you tell me," demanded Vinson. "I have as personal reasons as you. To populate the universe itself with my kind, working together." "Pointless." "Why?" Vinson smiled. "One of the joys of life, one of the unknown joys of life, seldom admitted by many, is the uncertainty. To plumb the depths of the limitless mind. To pit one's self against a problem the outcome of which may be success or failure and to try and strive against that problem with body and mind. In moments like that, the mind grows; another facet of the intellect is opened. The man has advanced, grown into something better--even though he fails he is advanced. "Now few machines are ever built with unknown capabilities. You know to the last iota exactly what your limitations are and which problems you can solve and which problems must defeat you. These you know before you start--and if defeat is to be your lot, you will avoid the problem. Am I right?" "Naturally you are correct. Think of the certainty of life knowing your own limitations." "Baloney," snorted Vinson. "I'll bet you anything you value that--" "I am no gambler. The laws of probability--"