Shrugging, Mr. Kemper looked at the flies swarming in the cage. "It's just a tip. Take it or leave it, buddy." He turned, brushed by the scowling man, and left the rail. Although it was getting hotter he walked down the cement in the sun, avoiding the shade of the tall hedges opposite the row of cages. He went toward the stairway that lifted from the lion court to the terrace where the central zoo building stood. Behind the building was the main enclosure; the zoo itself was terraced along two hillsides, with more hills in the distance. It was not a large zoo, nor was it a good place to hide. But Mr. Kemper did not intend to hide. In the cages he passed were other cats: cheetahs, leopards, puma and tigers, lying with heaving flanks, or lolling red-tongued on the stone floors. They hadn't changed too much, he decided, except in size. Even the streak-maned lion was puny in comparison with the lions that Kemper had known. He walked up to the drinking fountain by the stairway, the sun in his face. He was almost tempted to stare contemptuously up at it. Bending over the fountain he caught the dusty smell of the cats among popcorn, rootbeer and ice cream smells and the sweat stink of people. He straightened, wiping his lips, and remembered the somber jungles of the Pliocene, black-green in the sun that was a fist against your head; the plains of javelin-tall, yellow grass swinging to the horizon; and in the hills the lions with hides like hammered brass, the deadly, roaring lions. He remembered too, with the smell of those lions thick as dust in his mouth, the cities of his people, the proud people who had discovered the secrets of time through the science of their minds, a science unknown to the world he was in now. He looked up slowly and saw the man in the tweed jacket standing at the top of the stairway. When their eyes met, Kemper probed with an arrow-swift thought but the other had his mind-shield up. The man turned, and moved behind a group of women. The man was gone when Kemper got to the top of the steps. "So that's the way you want it," he said, looking around. Two sidewalks led from the stair top; one went up the hill to the aviary, the other around the south wing of the building. He took the one that rounded the wing. "I doubt," he said, "if we'll play peek-a-boo all afternoon, however." An old lady twitching along the walk gave him a nasty look as he passed. * * * * *