"lifting" Pillbot into the fourth dimension. Belatedly, he knew that the cutout which he held dangling, resembled Pillbot in outline.

Harper dashed back and forth in little rushes, carrying the paper figure. He dared not put it down, for fear of seeing some segment of Pillbot flash back. He did not know what to do with it.

Finally he compromised by suspending it to a low hanging chandelier, where it dangled swaying in the slight air currents.

Gault was watching his assistant's antics with a bleak expression that changed to sardonic satisfaction as he realized Pillbot was in a predicament like his—only more so. Abruptly he frowned, staring ahead, and Harper guessed that Pillbot had located Gault's torso in the other realm, was nudging him to indicate the fact.

Suddenly Harper knew that he himself must enter this fourth dimensional realm. That strange instinct told him the solution to everything was there—somewhat as a woman's intuition impels her to act in a certain way, without knowing why.

How to get there? Another paper cutout? He glanced toward the Professor—the occupied trousers, and swimming above it, the man's head. The head was watching him, the expression savage.

No, there must be no more cutouts, Harper decided. While the four dimensional entity distinguished between the outlines of a thin silhouette and a fat one, something in between, like Harper's form, would be testing It too far.

He, Harper would take the place of his own cutout!

Gault's head reared up, glared fixedly at his assistant as the young man swung his legs onto the desk, then lay down flat. A moment he lay there, in "Flatland"—then leaped to his feet.

It was as though he had leaped into a different world. He was no longer in the laboratory. He wasn't on any, floor at all, as far as he could make out. His feet rested on nothing—and yet there was some sort of tension under him—like the surface tension of water.

He was—he suddenly knew it—standing on a segment of warped space! There was a spacial strain here that acted as a solid beneath him!

Harper looked "up"—that is, overhead. There was nothing there but vast stretches of emptiness—at first. Then he saw that this emptiness was lined and laced with filmy striations, like cellophane. They bore a strange resemblance to his "doodlings," as though that strange faculty of his enabled him to somehow perceive this place of the fourth dimension. And instinctively Harper knew that these lacings were the boundaries of a vast enclosure—a four dimensional enclosure, the "walls" of which consisted of joined and meshed space-warps.

Abruptly he became aware of movement. He became aware of solidity there above him. And the solidity was in motion.

Harper knew he was gazing upon a being of the fourth dimension—doubtless the Entity that had caused the phenomena in the laboratory, which had snatched him into the fourth dimension, and was even now observing him with its four dimensional sight! There was a shape above him that strained his eyes, gave hint of Form just beyond his comprehension.

Harper hardly noticed that Pillbot was beside him, shaking him. He had suddenly grasped a fundamental law of spacial stresses, and he whipped out a pad and pencil, began scribbling down the mathematical formula of these laws. He began to see now why skyscrapers encountered the "stress-barrier" at a certain height. He understood it just as a person of innate musical ability, hearing music for the first time, would understand the laws of that music.

"Look out, It's moving, descending!" Pillbot was yelling into his ear. "It is about to act. Became active the moment you got here. How did you induce it to bring you here?"

"Huh?" Harper looked up from his scribbling. "Oh." Harper explained quickly how he had induced the Being to act on himself.

"That's it!" cried Pillbot hoarsely. "You switched the pattern of imitation on It—tricked It into bringing you here. That's what made