"We injected fluids," Vasper told him. "You see, Kenley, we assimilate food here now chiefly in liquid form. Now the screen--we have reduced a margin of absolute zero between the walls of the screen, to a width that your obsolete measuring system cannot cover. The screen itself is not a physical wall. It is--well, unspatial. That is too advanced for either of you to grasp now. It is sufficient to explain that you touch the absolute zero wall, and are revived, all so instantaneously, that you are not conscious of the change. And in that transition, you reach any destination you head for." "Simple," Jim groaned. "So very, very simple. Okay, and I thought Aladdin--or whoever he was, just happened to be a myth." Jim studied Vasper thoughtfully. "And now, my good friend, why are we here?" "You," Vasper announced, "are here because of your friend Winslow. We are few, and we need brains, and fit bodies. Winslow has both. We search the back centuries constantly for men--and women. Men with brains to keep our race, and our world existing. We placed the skydome over all our cities because the sun will cool for a thousand years. We have learned that and must start now, to keep our plant and animal life from perishing, till the cycle ends and the earth grows hot again. You, Jim Kenley, were brought along because you are Winslow's friend, and your company will be of advantage while he adjusts himself to what must be an amazing change in his career." "A master work of understatement," Bob observed. "Maybe I was serving my time to better purpose. It was all I wanted to do. Do you think I'm ever to be happy here?" "What sort of ball clubs do you have?" Jim fired at Vasper. "I'll bet there's not even a golf club." Vasper laughed. "You're due for some surprises, Kenley." For Bob Winslow, there followed hours that intrigued him. Only here and there did he meet Taval residents. Vasper explained that by going directly from point to point, that there was no traffic, that all duty hours were staggered because Taval at night, was as well illuminated as by day. The chief plants were operated by robot workers, who could reproduce their kind in other factories. "Taval, like our other cities, now needs only brains," Vasper went on. "We maintain sports here to keep our bodies fit." As he spoke, Vasper undid a tiny container hanging to one shoulder, extracted a handful of tiny pellets and swallowed them. At Bob's look of curiosity he smiled. "Energy," he said. "But we use more fluid food than these. Come, while I take you to The Three, your companion is at liberty to go across there to the stadium of sports."