Sailor's honor, Maia thought. He's bound to warn me that he may have to turn on me, later. It's a strange code.

"You know they can't afford to let you go," she said, pressing the point. "You've seen too much. They can't let their personal identities be known."

"That, too, depends," Poulandres said cryptically. "Right now, the important thing is that we've won a little time."

But what happens when no time remains? When the reavers run out of patience? "Fire or water," Baltha said. And if those don't work — if they can't pry us out by themselves — I wouldn't put it past them to send for help. Perhaps even calling their enemies.

It wasn't farfetched to imagine the gang striking a deal with their political opposites, the Perkinites, in exchange for whatever it might take to tear this rocky citadel apart. In the end, both extremes had more in common with each other than either did with the middle.

The navigator's dark young features relaxed in relief when they rounded the corner, and he put the weapon back on safety. Leie embraced Maia, and she felt her shoulders relax a fierce tightness that had gone unnoticed till now. "Come on," Maia told her twin. "Let's get back to work."

But it was hard concentrating at first, when Maia stood once more before the massive stone dais, looking alternately at the little sextant and the vast, ever-changing world-wall. Her task was to find a miracle, some way to follow Renna out of here. Yet, Baltha's offer and Poulandres's disturbing answer unnerved her. Suppose she did manage to solve the problem. Might that only doom Renna, and in the end prove futile for them all?

Soon, the fascinating vista of ever-changing patterns overcame her resistance, drawing her in. So much so that she hardly noticed when the string of faint bulbs came on again at the back of the room, evidence that the reavers were at least considering further discussion.

It was Leie who made the next breakthrough, when she discovered that the sextant could be used to change the wall scene. Fiddling with the finely graded dials, which Maia normally used to read the relative angles of stars, Leie turned one while the little tool was attached to the data plug. At once the patterns shifted, left and right! They moved up when she twisted the other wheel, disappearing off the top edge of the display, while new forms crowded in from below.

"Terrific!" Maia commented, trying for herself. This verified what she had suspected, that the great wall-screen was only a window onto something much vaster — a simulated realm extending far past the rectangular edges before them. Its theoretical limits might stretch hundreds of figurative meters beyond this room. Perhaps there were no limits at all.

The eye kept grasping for analogies amid the swirling patterns. One instant, they were intertwining hairy fingers. The next, they collided ecstatically like frothy waves breaking on a seashore. Rolling, convoluted configurations writhed without hindrance across the borders of the display. By turning a little wheel on the sextant, the humans might follow, but only in abstract, as observers. Only the shapes themselves knew true liberty. They appeared to have no needs, to fear no threats, to admit no physical bounds. The thought conveyed to Maia a sense of untold freedom, which she envied.

Did Renna somehow change himself? She wondered. Did he know a secret way to join the world in there, leaving this one of rock and flesh behind? It was a fantastic notion. But who knew what powers the Phylum had developed during the millennia since the Founders established a world of pastoral stability on Stratos, turning away from the "madness" of a scientific age.

On a hunch, Maia tried pushing the buttons they had found earlier, near the little holes in the massive podium. But they proved as useless as before. Perhaps they really had once controlled something as mundane as the room lights.

Then Leie made another discovery. By bending one of the sextant's sighting arms, another kind of simulated movement became possible. Of the men who had been watching, transfixed, several moaned aloud in awe as the shared point of view suddenly appeared to dive forward, plunging past billowing foreground simulacra, plowing through objects as intangible as clouds.

Maia felt it, too. A wave of vertigo, as if they were all falling together through an infinite sky. Gasping momentarily, she had to turn her eyes away and found that her hands were gripping the stone podium like vices. A glance at the others showed she wasn't alone. The earlier breakthroughs had been stunning, but not like this. Never had she heard of a Life-like simulation in three dimensions! The rate of "fall" appeared to accelerate. Shapes that had dominated the scene grew larger, revealing minutia of their convoluted forms. The centermost structures ballooned outward, while those at the fringes vanished over the edge.

The falling sensation was an illusion, of course, and with a little concentration, Maia was able to make it evaporate in a sudden mental readjustment. Moving "forward" seemed now to be an exercise in exploring detail. Any object centered before them was subject to expanding scrutiny, revealing ever-finer structures within . . . and then finer still. There seemed no limit to how minutely a formation could be parsed.

"Stop . . ." Maia worked hard to swallow. "Leie, stop. Go the other way."

Her sister turned and grinned at her. "Isn't this great? I never imagined men had such things! Did you say something?"

"I said, stop and back up!"

"Don't be afraid, Maia. As you explained to me, it's just simulated—"

"I'm not afraid! Just reverse the controls and back away. Do it now."

Leie's eyebrows raised. "As you say, Maia. Reversing course." She stopped pushing and started pulling gently at the little metal arm. The appearance of a forward plunge slowed, arrested, and began to withdraw. Now curling patterns in the middle receded, diminishing toward a central vanishing point while more and more bright, complex objects swarmed in from the periphery. The visceral sensation was one of pulling away, of rising up, so that each passing second meant they attained a larger, more godlike view.

It was a briefly glorious sensation, as Maia imagined it might be like to fly. Moreover, she felt a sense of restored contact with Renna, if only by sharing this thing he must also have delighted in.

At the same time, another part of her felt overwhelmed. Renna had explained that the Game of Life was only among the simplest of a vast family of pattern-generating systems, called cellular automata. When the big wall first came alight, Maia had hoped the sailors and their books might help solve this vastly more complex "ecosystem," despite none of them being savants. But if the men had been as baffled as she by the former intricacy, this addition of a third dimension shattered all hopes of easy analysis.

In her heart, Maia felt certain there were comprehensible rules. Something in the patterns — their diverging yet oddly repetitious sweeps and curls — called this intuition to her. I could solve it, she was sure. If I had the computer-cd game board to work with, instead of this balky little sextant, and as many hours as Renna had in here, alone. And some of his knowledge of math.

Alas, her list of deficits exceeded assets. In frustration, she pounded the table, jiggering the little tool. "Hey!" Leie shouted, and went on to complain that it wasn't easy piloting gently enough to keep it all from becoming a vast blur, the sextant's wheels and arms were old, loose, in need of ample mechanical repair. Someone had let the poor machine go straight to pot, Leie insinuated over her shoulder. It's a wonder it still works at all, Maia thought. At first, she had been awed by the coincidence, that her old, secondhand navigation tool could be used in this way. But then, many older instruments she had seen on shipboard featured diminutive blank windows. In former times, it must have been customary to hook up to the Old Network frequently . . . although Maia doubted spectacular wonder-walls were ever common, even before the Great Defense. Or the Founding, for that matter.