T is for Topology. H is for heartsick hunger. Abruptly, the Reimann fold became a concrete visualization. As though printed clearly in and around the air, which was simultaneously both around him and not around him, which existed/not existed in spacetime, he saw the sideslip diagram. He twisted. Spring had come to Riya's world; spring and the thousand sounds of it. The melted snow in the mountaintops ran down in traceries of leaping water, and the spring-crests raced along the creeks into the rivers. The riverbank grasses sprang into life; the plains turned green again. Riya made her way up the path across the foothills, conscious of her shame. The green plain below her was dotted, two by two, with the figures of her people. It was spring, and Time. Only she was alone. There was a special significance in the fact that she was here on this path in this season. The plains on either side of the brown river were her people's territory. During the summer, the couples ranged over the grass until the dams were ready to drop their calves. Then it became the bulls' duty to forage for their entire families until the youngsters were able to travel south to the winter range. Through the space of years, the people had increased in numbers, the pressure of this steady growth making itself felt as the yearlings filled out on the winter range. It had become usual, as the slow drift northward was made toward the end of winter, for some of the people to split away from the main body and range beyond the gray mountains that marked the western limits of the old territories. Since these wanderers were usually the most willful and headstrong, they were regarded as quasi-outcasts by the more settled people of the old range. But—and here Riya felt the shame pierce more strongly than ever—they had their uses, occasionally. Preoccupied in her shame, she involuntarily turned her head downward, anxious that none of the people be staring derisively upward at the shaggy brown hump of fur that was she, toiling up the path. She was not the first—but that was meaningless. That other female people had been ugly or old, that the same unforgotten force that urged her up the mountain path had brought others here before her, meant only that she was incapable of accepting the verdict of the years that had thinned her pelt, dimmed her eyes, and broken the smooth rhythm of her