Beyond those areas, according to the robot patrols which had reconnoitered there, nothing lived. Nothing could. No protoplasmic being could exist under the direct rays of the Blue Sun. Even the metal-and-translite bodies of a robot wouldn't long protect the sensitive mechanisms within from the furnace heat of the huge star. Each species had its niche in the World. Some, like the hurkle, lived in swamp water. Others lived in lakes and streams. Still others flew in the skies or roamed the surface or climbed the great trees. Some, like Dodeth's own people, lived beneath the surface. The one thing an intelligent species had to be most careful about was not to disturb the balance with their abilities, but to work to preserve it. In the past, there had been those who had built cities on the surface, but the cities had removed the natural growth from large areas, which, in turn, had forced the city people to import their food from outside the cities. And that had meant an enforced increase in the cultivation of the remaining soil, which destroyed the habitats of other animals, besides depleting the soil itself. The only sensible way was to live _under_ the farmlands, so that no man was ever more than a few hundred feet from the food supply. The Universal Motivator had chosen that their species should evolve in burrows beneath the surface, and if that was the niche chosen for Dodeth's people, then that was obviously where they should remain to keep the Balance. Of course, the snith, too, was an underground animal, though the tunnels were unlined. The snith's tunnels ran between and around the armored tunnels of Dodeth's people, so that each city surrounded the other without contact--if the burrows of the snith could properly be called a city. "Yerdeth Pell's residence," said Ardan. "Ah, yes." Dodeth, his thoughts interrupted, slid off the back of the robot and flexed his legs. "Wait here, Ardan. I'll be back in an hour or so." Then he scrambled over to the door which led to Yerdeth's apartment. [Illustration] * * * * * Twenty minutes later, Yerdeth Pell looked up from the data book facsimiles and scanned Dodeth's face with appraising eyes. "Very cute," he said at last, with a slight chuckle. "Now, what I want to know is: is someone playing a joke on you, or are you playing a joke on me?" Dodeth's eyelids slid upwards in a fast blink of surprise. "What do you mean?" "Why, these bathygraphs." Yerdeth rapped the bathygraphs with a wrinkled, horny hand. He was a good deal older than Dodeth, and his voice had a tendency to rasp a little when the frequency went above twenty thousand cycles. "They're very good, of course. _Very_ good. The models have very fine detail to them. The eyes, especially are good; they look as if they really _ought_ to be built that way." He smiled and looked up at Dodeth. Dodeth resisted an urge to ripple a stomp. "Well?" he said impatiently.