They left the plane and started in the direction of what once had obviously been a city. To Markten and his young aide the sight was nothing new; they had seen, as had all the other members of the Research Builders division, thousands of others just like the one toward which they were now walking. Sometimes Markten thought it would have been a lot easier to have signed up with the Production Builders division--but that would have been dull. Always searching for new plans: building something _new_--that was more to his taste. * * * * * The only trouble was, there seemed to be fewer and fewer new plans as the years went by. And now, even when you found some, you had to check its potentialities exhaustively before you started building it. Markten shuddered a little when he thought of some of the first things that had been built without preconstruction study for analysis as to its probable use. One of them would have blown New City off the face of the earth had it been put into operation in a metropolitan proving lab. Fortunately, the thing had been too big, and had been taken for trial to a lab located in a southern desert. Today, there was still a ten-mile wide crater in the sand where the thing had gone off. Production never got that model from Research. There were some others of similar nature that they hadn't got, too.... That was why, these days, even if you dug something up, you were damn careful before you built it. "Say, Markten!" "Yes?" "I was wondering about something. Eventually, we're bound to find all the plans there are. What happens when there aren't anymore?" "Maybe then there'll be time for that other stuff I caught you wasting time on in the ruin we were in last week!" There was a grin on Markten's thin face. "But not until!" "No, seriously, Markten. The division academy instructors said there wasn't much left, and that was why we had to be especially well trained, to find what little more there is. But what about after we do, and there just isn't anymore?" "Just--build more of what we've got, of course. What else would there be to do?" "Well--well, you must be right. But Production sure will be dull." * * * * * There was only a thin edge of the sun still separating daylight from darkness as they forced entry into their tenth ruin, and Markten's tone was dejected. "This," he said, "has been a day wasted, and there's little possibility that we'll come up with anything here. Better get out your night-lamp."