"And that--" Greg sobered. "That is another reason the others should dig into a good warm cave. It gets plenty cold during that eclipse period. An open camp on an exposed plain--" He shook his head. Maud Andrews said, "I can't understand why this satellite is habitable at all. I was under the impression that Saturn is a frozen planet." "It is. Its surface temperature is approximately 300° below zero, Fahrenheit. But the warmth of its numerous satellites is one of the astonishing discoveries made by the early space explorers, fifty or sixty years ago. Scientists have not yet explained the matter satisfactorily. Some say the tremendous mass of Saturn, the waves of atmospherics set up by its swirling motion and the 'grindstone' of its ring, form an electronic barrier-shield for the satellites. Still others believe that frigid Saturn acts as a gigantic mirror or solar reflector for its children." "But Greg--" That was Tommy O'Doul. "Why ain't there any colonies here if the climate's O.Q.? Men live on Venus, where it's hot as billy-be-hanged, and on Uranus, which is nothing but a ball of ice, and on a bunch of cold, airless asteroids--" "Economics, Tommy. The simple, single dictator of mankind's every venture. Venus has valuable vegetation, Uranus and the asteroids have important metals that can't be duplicated in Earth's laboratories, the asteroids have rare ore deposits. There is not--or at least there has not as yet been discovered--anything native to Titan that cannot be mined or made elsewhere more cheaply, more easily. Some day man's ever-expanding frontiers will claim this satellite as a colony, too. But now that the entire universe is open to man, the human race can increase a millionfold and _still_ allow every soul more _lebensraum_ than he can possibly use." Sparks Hannigan gazed at him admiringly. "It's stoo-pendous!" he said. "Titan? Not any more so than--" "Not Titan. You. You know everything, don't you? Pal--" Sparks shook his head. "I sure had you figgered wrong. I thought you was a soft-soaping dope. So then you got us off the _Carefree_ onto the skiff, cooled Breadon like a herring, declared yourself _It_ and made us like it--" Greg said, "Nonsense! I just happened to--Oh, nonsense! Shall we go into our new home?" But he flushed. By evening--Titan's short, grey shadowed evening, the only logical unit of duration by which they could live so long as they remained captive here--their new cave home began to take on some semblance of lived-inness. Vegetation was abundant on the hillsides. Sparks and Tommy had gathered heaps of dry faggots while Greg built a crude stone fireplace underneath the fluevent Sparks had reported; shortly thereafter the women had a cheerful blaze crackling on the hearth, and mingled with its grateful warmth was the odor of a savory stew, welcome scent to the nostrils of five who had worked long and hard in gathering the vegetables that had gone into that potage.