ousers, 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 mov