"But there may be nothing there," protested Greg. "That sun is younger than our Sun. The planets may not have cooled as yet. Life may not have developed." "In such a case," said Chambers, "we shall find another planetary system around another sun. A system that has cooled, where there is life." Russ gasped. Here was something important, something that should set a precedent. The first men to roam from star to star seeking new worlds. The first men to turn their backs on the old solar system and strike out in search of new worlds swinging in their paths around distant suns. Greg was saying, "All right, if that's the way you want it. I was hoping you'd come back with us. But we'll help you repair your ship. We'll give you all the supplies we can spare." Russ rose to his feet. "That," he said, "calls for a little drink." He opened a cabinet and took out bottles and glasses. "Only three," said Chambers. "Craven doesn't drink." Craven interrupted. "Pour one for me, too, Page." Chambers looked at the scientist, astounded. "I never knew you to take a drink in your life." Craven twisted his face into a grin. "This is a special occasion." * * * * * The _Invincible_ was nearing Mars, heading for Earth, which was still a greenish sphere far to one side of the flaming Sun. Russ watched the little green globe, thinking. Earth was home. To him it always would be home. But that would be changed soon. Just a few more generations, and, to millions upon millions of human beings, Earth no longer would be home. With the new material energy engines, life on every planet would be possible now, even easy. The cost of manufacture, mining, shipping across the vast distances between the planets would be only a fraction of what it had been when man had been forced to rely upon the unwieldy, expensive accumulator system of supplying life-giving power. Now Mars would have power of her own. Even Pluto could generate her own. And power was ... well, it was power. The power to live, the power to work, to establish and maintain commerce, to adjust gravity to Earth standard or to any standard. The power to remake and reshape and rebuild planetary conditions to suit man exactly. Earthmen and Earthwomen would be moving out en masse now to the new and virgin fields of endeavor--to the farms of Venus, to the manufacturing centers that were springing up on Mars, to the mines of the Jovian worlds, to the great laboratory plants that would spring up on Titan and on Pluto and on the other colder worlds.