She had once studied fraction spaces—individual dimensions operating without counterparts, and dimensions of less than unit numbers. Time without space; length without breadth, depth or time. Probability without extension. Half-spaces, quarter-spaces, spaces composed of irrational fractions. All to be handled by fractional transforms and fractal geometric analysis. She had even begun to chart the geodesics of higher fractional spaces, and the way these geodesics might project in five- and four-space.

She dropped her head between her knees. Her thoughts were zagging. No order, no discipline.

The corridor—just an extension of the sixth chamber machinery, designed for inertial damping.

On a journey of centuries, the Stoners had changed their minds, or perhaps lost sight of the original goals. A world unto itself, the Stone had impressed upon succeeding generations its own character, until it seemed perfectly natural to live in rotating cylinders, hollowed out of asteroid rock. In time, perhaps even the asteroid had seemed to fade out of immediate awareness, leaving only life within cylinders.

Squeezed and confined across centuries, nurtured by the perceptions of the Stone, the Stoners' genius erupted. They became nothing short of godlike, making their own universe, and shaping it in the image of the world they were most familiar with.

When they found a way out of the Stone without compromising the ultimate mission—

When they found they could create an incredible extension of their world—

Would any of the Stoners have been able to resist the temptation? (Yes. . . the orthodox Naderites—and they had stayed behind for a century.)

So the sixth chamber engineers, headed by the enigmatic Konrad Korzenowski, had created the corridor, imbued it with certain properties, played with its potentials. They had created the wells and found some way to fill the corridor with air and soil, with landscapes equal if not superior to the valley floors of their everyday lives.

Her body relaxed. She sat up. Some of the symbols in her as-yet-unwritten article made sense to her now; she could riddle their meaning. Her mind unfogged and she seemed to see all the problems interacting at once, like workers in a skyscraper with glass walls and floors.

The Stoners had created the corridor to relieve cramped conditions, confinement of the mind if not any real confinement of their personal space. (The records made it clear that the Stone had never become overcrowded.)

But the corridor—and this came to her abruptly, without precedent—the corridor carried a certain unexpected liability, a side effect they might not have been aware of at first. . . .

Or never became aware of.

By creating the corridor, they had knocked the Stone out of its own continuum. The image that came to mind—all too irritatingly specific, since she wasn't at all sure it was accurate—was that of the corridor as a length of whip, and the Stone as the tip. With the creation of the whip, and its inevitable uncoiling in superspace, the tip had been snapped out of one universe—