"We don't know how our velocity matches this thing," said Kim after an instant. "We could be drifting toward the edge of the shadow. You watch the stars all around. Make sure I head directly for that blackness. When we touch, I'll see what I can find out."
He reversed the ship's direction. He let the Starshine float down backward. The mass of unsubstantial darkness seemed to swell. It engulfed more and more of the cosmos....
A long, long time later, there was a strange sensation in the feel of things. Dona gave a little cry.
"Kim! I feel queer! So queer!"
Kim moved heavily. His body resisted any attempt at motion, and yet he felt a horrible tension within him, as if every molecule were attempting to fly apart from every other molecule. The controls of the ship moved sluggishly. Each part of each device seemed to have a vast inertia. But the controls did yield. The drive did come on. A little later the sensation ended. But both Kim and Dona felt utterly exhausted.
"It—was getting dark, too," said Dona. She trembled.
"When we tried to move," said Kim, "our arms had a tendency to move at right angles to the way we wanted them to—at all the possible right angles at once. That was the edge of the shield, Dona. Now we'll see what we've got."
He uncovered the recording cabinet. There had been no need to set up instruments especially for the analysis of the field. They had been a part of the Starshine's original design for exploration. Now Kim read the records.
"Cosmic-ray intensity went down," he reported, studying the tapes. "The dielectric constant of space changed. It just soared up. The relationship of mass to inertia. That particular gadget never recorded anything significant before, Dona. In theory it should have detected space-warps. Actually, it never amounted to anything but a quantitative measure of gravitation on a planet one landed on. But it went wild in that field! And here! Look!"
He exultantly held out a paper recording.