SWEEPER Dan looked at this for a moment. Then, frowning, he strode on. In his mind's eye, he was seeing the sign by the road: Care High-Speed Vehicles Only —Swept— Dan couldn't decide whether the word "Swept" was part of the warning or just an afterthought. In any case, he had plainly heard a struggle here and now there was nothing to be seen. Alert for more brass plates, he wound his way through the streets until he came out on a broad avenue. On the opposite side were a number of tall, many-windowed buildings like apartment houses. On the sidewalks and small lawns in front, crowds of children were playing. They were wearing low boots, leather shorts or skirts, brightly colored blouses and hose, and yellow capes. Walking quietly among them was a tawny animal with the look and lordly manner of a lion. It was a lion. As far as the rapidly dispersing fog let him see, the avenue ran straight in one direction. In the other, it ended a block or so away. Apparently the crooked, wind-breaking streets were only on the edge of the city. Dan thought of the questions Kielgaard wanted him to answer: 1, how do the Porcyns keep the size of their population down? 2, what is the connection between rejuvenation and Vacation Planet? 3, do the Porcyns have a proper mercantile attitude? Are they likely to make an agreement? Will they keep one they do make? To find the answers, Dan intended to work his way carefully through the city. If nothing went wrong, he should be able to see enough to eliminate most of the possibilities. Already he had seen enough to make Porcyns look unpromising. The rigid city boundary, the strict uniformity of the buildings and the uniform pattern of the clothing suggested a case-hardened, ingrown way of living. Across the street, a low door to one side of the apartment building's main entrance came open. The lion walked out. It was carrying a squirming little boy by his bunched-up cape. The big creature flopped down, pinned the struggling boy with a huge paw and methodically started to clean him. The rasp of the animal's tongue could be heard clearly across the street. The boy yelled. A healthy-looking girl of about twelve,