“And when I found the nature of that experiment I was astounded. He had been attempting to follow up the sparse details given in the inscription and rediscover the method of changing size. And he had done it! He showed me the apparatus he had worked out, a compact black case which strapped around his chest and which would cause everything within its field of action to grow or decrease in size. And standing there on the hilltop, he grew in size until he towered up a giant of a hundred feet, then dwindled until he was an inch in height, a tiny manikin.

“He was exultant, and I thought that at last he would leave the hilltop and cover the sand-grain once more. I pointed out to him what good he might accomplish in the world with that great power, but he only snarled at me and for the first time revealed his intention. He was planning to dwindle in size until he could enter that atomic world, to go down into the sand-grain, to the atomic universe.

“Short of force, I used all my efforts to prevent him, for I was aghast at such a plan. But he went on, unheeding, making his preparations for the trip. He dug out and removed the little circle of blocks around the sand-grain, then gradually began to dwindle in size until he was a tiny figure a few inches high, standing on the metal circle near the grain of sand. Smaller and smaller he became, until he vanished entirely from my sight, and I knew that he had entered the sand-grain.

“For three days I watched beside the stone cube, waiting for his return. It was toward evening of the third day that he finally came back, a tiny upright form on the metal plate that grew swiftly to the man I knew. He had come back.

“He had come back—but changed. He seemed to be filled with an immense excitement, to be spurred on by some hidden purpose. He gave small answer to my flood of questions. He had found the atomic world, had been guided down into that particular atom of the grain by ‘certain signs,’ a phrase which he did not explain. As to the people of the atom, he said only that there were many of them and that they were “different.” More he would not tell me, and my fear, my misgivings, increased.

***

“The night of disaster rushed upon us, a week after his return. I was asleep in the cabin while Powell worked, as I thought, in the laboratory. Sometime after midnight I woke and sensed that Powell was not in the cabin. I dressed hurriedly and found that he was not in the laboratory either. Instantly I knew where he was and hurried up to the hilltop, and to the pit on that hilltop that held the stone cube and the sand-grain.