Livia had sunbathed on these sands many times, and canoed with friends on those net-strewn waters. She had never imagined this place existed parallel to the lake she knew.

Drumbeats started up somewhere among the long-houses. "We must hurry now," said Qiingi. "The potlatch of the ancestors is about to begin." He hurried into the city, greeting people left and right as he went.

Lucius and Livia smiled and nodded at Raven's people, who grinned and talked about them as they passed.

Children raced alongside them, laughing and screaming in mock fear. Ahead, a crowd was growing.

"You're a very bad man," Livia said. "Bringing me out here on a pretext, then kidnapping me!" But I am having fun, she was about to add, when she saw that he wasn't laughing. Indeed, he looked tired, and maybe even a bit frightened.

"Lucius, what's wrong?"

People were now appearing from all over — some blinking into view from whatever submanifold they had been inhabiting. All were converging on the great open circle that lay ahead. Lucius shook his head, and looked away from Livia.

"I had no one else I could trust with this," he said. "Nobody I knew who might understand. Except you."

"What do you mean?"

"Look at this!" He waved at the fabulous totems and rearing longhouses that surrounded them. "It's wondrous, isn't it — and you never knew it was here! Livia, don't you feel even the slightest bit claustrophobic living in just one manifold?"

She nodded, eager to have someone agreeing with her for a change. "Everyone says that Westerhaven is the most cosmopolitan place in Teven. We visit other manifolds, sure — but how many of them? What you were saying earlier about us being butterfly collectors ... I know what you mean. We see the world only from our own narrow perspective. We're tourists in other people's realities."

He nodded enthusiastically. "I heard your friend Aaron Varese speaking in Barrastea last week. He was proposing that we eliminate manifolds altogether."

She laughed, a bit uncertainly. "He's just trying to stir things up. It's just not possible. Worldviews don't mix."

"Don't they?" He stared at her with an intensity she had never seen before, as if he were about to start yelling — or running. "Are you sure about that?"

"Lucius ... I don't ... "

Livia heard pounding feet, shouts. The noises came from the plaza they were approaching. People were crowded around its outskirts, all talking at once, some hopping up and down to see over others. The drumbeat was seductive; the musician in her responded, analyzing its meter even as her imagination half consciously wove melodies and patterns around it.

Qiingi waved to them. "The potlatch begins!" He was obviously excited, but from the way he kept looking about himself it was clear he was a bit nervous, too. By now the crowd was pressing in on all sides. Lucius grabbed Livia's arm.

"Stay close," he said. "I don't know how far this will go"

"What — " But he pressed on ahead through the crowd, and she followed. Livia had never been in such a strange situation, surrounded by people in buckskins and beads, permeated with the smells of woodsmoke, chicken fat, and tanned leather.

Silence fell suddenly; then a collective gasp rose from the crowd. Lucius let go of Livia's arm and she staggered to a halt She was close to the front of the circle, and peered past a tanned shoulder to see what was happening.

All across the earthen plaza, ghostly figures wavered into existence. At first there were only a handful, but in seconds there were dozens, then scores of them.

The ancestors filled up the plaza, and they came bearing Impossible gifts.

They were too perfect to be human. Of course, in her lifetime Livia had seen people wrapped in many guises — as idealized sexual objects, as animals, as fabulous mythical beasts. She had seen people pretend to be angels. These ancestors didn't seem to be pretending.

She could see a kind of shimmering arch above and around the plaza; outside it, the world looked ordinary — that is, it was filled with wise trees, hollow-eyed birds that might in the blink of an eye transform into lynxes and bound away into the underbrush. Raven's world. Within the arch the plaza was still there, and in it stood beautiful, smiling men and women. That was fine; people could appear in mid-manifold like that But in their hands, and around and above them, were things that could not exist here.

One woman stood next to a man-sized, chrome robot that looked around itself curiously with big lens-eyes. Substitutes for human labor were limited even in technophilic Westerhaven, yet here a robot stood where properly it could not be. Another of the strangers held up a big device Livia recognized as a laser saw; at least, she hoped that was all it was. Piled around the strangers' feet were all manner of machines, livedevices, and mobile bots.

The tech locks should be disabling, removing, or hiding all these things. Livia kept waiting for the gifts — for if this was a potlatch, then that was what these things were — to flicker and go out, the way that Rene had on the road to the drummers' city. It didn't happen.

She found herself blinking again and again, and backing away. Around the edge of the circle other people were doing the same. It was like looking at an object and it refusing to come into focus, even while everything around it became sharp. Control of reality should be as automatic as sight; it had been that way for Livia all her life.

Except once.

She found she had turned and was trying to run. Stop! she commanded herself. You mastered this fear! Or she'd thought she had. With an effort she turned back to look at the circle.

The closer she looked the worse it was. Some of the strangers were suffused in a golden glow that came from the clouds of programmable matter that suspended them as if they were weightless, ten or fifteen centimeters above the ground. The quantum dots composing the virtual matter swirled and glowed, making them appear like pillars made of countless infinitesimal stars — ostentatious, mat, even gauche, given that the ordinary angels of Westerhaven were composed of just such fogs, but were careful to remain invisible. Embedded in the fogs were many strange objects: globes and rods of crystal and metal, things with handgrips that might be weapons; and humming, flittering things that could be alive but for the fact that they gleamed like bronze.

At an unspoken signal the strangers began to walk toward the crowd.

She became aware that Qiingi was standing next to her. "I didn't really believe it would happen," he said softly. "They have broken the walls of the world." He didn't sound happy.

It's not like after the accident, Livia was telling herself. This isn't a crash. It's controlled, somehow.

As the first of the "ancestors" stepped outside the earthen circle the crowd came to life. A sudden madness seemed to sweep them and Livia found herself getting caught up in it Some people were shouting, shaking their fists. Others were laughing and crying. Was this a miracle or a nightmare? No one seemed to know.

As she edged back through the crowd, livia realized that Lucius was missing. He was taller than most of these people. He should be visible.

Someone jostled her; she grabbed Qiingi's arm so as not to lose him, too. "But what are they? What are they doing here?"

He shrugged uncertainly. "Our founders have blessed their presence. They call them ancestors; so I must accept that this is what they are."

"But where did they come from?"

He looked at her and for a moment his composure almost broke. He was frightened, she realized with a chill. "Wordweaver Kodaly," he said stiffly, "if they are our ancestors, men they have always been here."

More of the strange people were appearing by the moment; as each waded into the crowd, he or she would stop to speak to people. As the ancestors spoke, they reached about in a leisurely way, picking now this, now that item from their belts or materializing it out of the fog of virtual matter, and handing it to the person they were talking to. The one closest to Livia was male, and had a sonorous voice; and it was a real voice, not processed by inscape. He turned his head and his eyes met Livia's. She felt the gaze as a shock.