They speeded their time rate now, and flashed toward Earth at enormous speed that brought them within the atmosphere in minutes. They had landed in the valley of the Nile. Arcot had suggested this as a means of determining the advancement of life of man. Man had evidently established some of his earliest civilizations in this valley where water and sun for his food plants were assured. "Look--there _are_ men here!" exclaimed Wade. Indeed, below them were villages, of crude huts made of timber and stone and mud. Rubble work walls, for they needed little shelter here, and the people were but savages. "Shall we land?" asked Arcot, his voice a bit unsteady with suppressed excitement. "Of course!" replied Morey without turning from his station at the window. Below them now, less than half a mile down on the patchwork of the Nile valley, men were standing, staring up, collecting in little groups, gesticulating toward the strange thing that had materialized in the air above them. "Does every one agree that we land?" asked Arcot. There were no dissenting voices, and the ship sank gently toward a road below and to the left. A little knot of watchers broke, and they fled in terror as the great machine approached, crying out to their friends, casting affrighted glances at the huge, shining monster behind them. Without a jar the mighty weight of the ship touched the soil of its native planet, touched it fifty millenniums before it was made, five hundred centuries before it left! Arcot's brow furrowed. "There is one thing puzzles me--I can't see how we can come back. Don't you see, Morey, we have disturbed the lives of those people. We have affected history. This must be written into the history that exists. "This seems to banish the idea of free thought. We have changed history, yet history is that which is already done! "Had I never been born, had--but I _was_ already--I existed fifty-eighty thousand years before I was born!" "Let's go out and think about that later. We'll go to a psych hospital, if we don't stop thinking about problems of space and time for a little while. We need some kind of relaxation." "I suggest that we take our weapons with us. These men may have weapons of chemical nature, such as poisons injected into the flesh on small sticks hurled either by a spring device or by pneumatic pressure of the lungs," said Stel Felso Theu as he rose from his seat unstrapping himself. "Arrows and blow-guns we call 'em. But it's a good idea, Stel Felso, and I think we will," replied Arcot. "Let's not all go out at once, and the first group to go out goes out on foot, so they won't be scared off by our flying around." Arcot, Wade, Zezdon Afthen, and Stel Felso Theu went out. The natives had retreated to a respectful distance, and were now standing about, looking on, chattering to themselves. They were edging nearer. "Growing bold," grinned Wade.