Martt apprehensively glanced behind. A wall of dwindling rock was coming after them. The drug in these larger doses seemed acting with a multiplied power. The scene was a dizzy swirl of movement. Mountains closing in everywhere. To Martt came a flash of terror. They would be crushed. Their bodies were growing tremendously to fill this constricted space. . . . Degg had stopped walking. They were gathered in a group. They were now in the center of a circular valley, with a ring of mountains closing in. A ten-mile valley . . . a mile . . . a hundred feet. . . . But the mountains shrank to hills; to a low cliff-wall--a ridge. . . . It closed in. . . . "Now!" shouted Degg. They leaped over the low ledge of encircling rock; scrambled over it and fell on a level ground above. . . . Beside them Martt saw a small jagged hole in the ground. . . . The size of his waist . . . his fist . . . his finger. . . . It dwindled, closed and was gone; while again, above them and all about, were black, empty spaces, filled soon with shrinking canyons out of which hastily they climbed. . . . A fantasmagoria of climbing, struggling upward to avoid being crushed by their own growth. . . . There was a canyon too narrow, with sides too high. . . . They had to stop their growth, and climb its jagged, precipitous side. The climb took hours. There was another meal, while Martt slept and Zee remained on guard. Then another valley. Broad, with a steeply inclined floor. They grew out of it; into another; and another. . . . Martt became conscious of a change in the air. Cooler, with a dankness. And now at last, overhead the void was no longer black. A suggestion of purple. And suddenly as they leaped from a chasm which shrank and closed under them, Martt saw a sky. Somber purple, with stars. A new conception of it all swept Martt. His Earth--the stars of its Universe. The Inner Surface of the Atom, Zee's realm--millions of times larger. And now--compared to Reaf . . . was he now a million times the size of Reaf? . . . Or a million million? Largeness, unfathomable. A convex world out here. The surface of a globe, whirling in Space. And overhead, still other stars, so gigantic--so remote! V Martt gazed curiously around. They were at last in Degg's world--the region of the Arcs. A tumbled land of crags upon which lay a gray-black snow. Martt's heart sank before its utter desolation--a tumbled waste, upheaved as though by some cataclysm of nature. Desolation! And as though to veil it, a fall of blackish snow--a somber, tragic shroud. It was night. And, Martt surmised, a winter season. Yet the air was not cold; merely dank. And the snow seemed not cold, congealed perhaps by the dank, heavy air; but to Martt's touch, not cold, no more than chill. With her bare limbs and filmy veiling, Zee was shivering. Martt discarded his jacket, but she did not want it. He said, "But you must be cold, Zee."