She knew where to begin. If the corridor wasn't made of matter, there were only a few alternatives. Either it was a tube of restraining forces, passing beyond the end of the asteroid through some superspace trickery, or it was not. If not, then it was likely to be constructed itself of superspace trickery. (She considered, and dismissed as philosophically useless—for the moment—the notion that the corridor was an illusion.)

Superspace trickery was the more difficult concept to work with. If the Stoners had used the machinery in the sixth chamber to distort space-time, there would be consequences. When the multi-meter arrived—if it did what she had requested—she could begin laying down parameters. Curved space on the scale of the corridor would probably produce fluctuations in the value of pi, since the diameter of a circle, in any seriously distorted manifold, would vary in relation to its circumference. Other constants would vary depending on distortions in higher geometries.

She gave up trying to force the state after a while. The facts weren't sufficient to warrant straining herself.

There was nothing she could do, for the moment, but relax and read. She plugged another memory block into the slate.

"How long did it take you to get used to living without night?" Patricia asked. Farley tapped her fingers impatiently against the wall of the arch, waiting for the axis elevator. They stood fifty meters east of the tunnel ramp, on a smooth-polished square of nickel-iron.

"I'm not sure I am used to it," Farley said. "I live with it, but I miss starry nights."

"With all their technology, you'd think the Stoners would have come up with some way to have darkness."

"Shutting off the plasma tube would be a huge waste of energy," Farley mused. "Especially for the seventh chamber. I mean it does seem to go on forever—and how could you shut off something like that?"

Patricia pulled out her slate and typed, Seventh chamber plasma tube—power supply? Maintenance? Same as other chamber tubes?

The elevator door opened and they entered the large circular cabin. The door closed as Farley pressed a button. They both grasped bars mounted in the walls. At first, the acceleration of the elevator increased their total weight, but as they rose—approaching the axis—the effects canceled out. The elevator reached a steady velocity after traveling about a third of the way up the shaft. Their weight had decreased considerably by then. Shortly after, they began to decelerate, slipping smoothly into near-weightlessness. The door opened and a guard in black and gray greeted them.

The axis compartments surrounding the seventh chamber bore hole had been pressurized and heated, but otherwise they remained much as the Stoners had left them, centuries before. Ribbons of newly wired lighting crisscrossed the cavernous staging area.

"We're going to the singularity monitor," Farley said. The soldier gestured for them to board a cart. They followed the ropes and took their seats, buckling themselves in.

"I have a feeling you're going to show me something else astonishing," Patricia said accusingly. "I'm not even used to the other wonders yet."