He hesitated. "It felt odd. The surfaces seemed to flow around me." He grinned, his confidence recovering. "It was adjusting to me, I suppose. It was disconcerting, but it didn't last long... What do you think these levers are for?" His ma.s.sive fists hovered over the rods protruding from the seat-arms.

"No!" She laid her hands over his.

After a moment he relaxed and lifted his hands away from the levers, leaving them untouched. "Interesting," he said mildly. "These look just like the control levers in the 'Flying Pig.' Maybe there are some basic commonalities of human design, a certain way things just have to be..."

"But," she said firmly, "unlike with the 'Pig' we don't have the faintest idea what these controls are for."

Hork looked like a reprimanded child. "Well, as you told me earlier, we're not going to make any progress unless we take a few chances." He glanced down at the arrow device inset in the left arm of the seat. "What about this, for instance?"

Dura Waved closer. The arrow was a finger-thick cylinder hinged at its center; it lay at the heart of a small crater gouged out of the chair. The crater's rim was marked by a band divided into four quarters: white, light gray, dark gray, black. The arrow was pointing at the black quadrant. It seemed obvious that the arrow was designed to be twisted by the occupant of the chair.

Hork looked up at her. "Well? This seems harmless enough."

Dura suppressed a manic giggle. "You haven't the faintest idea what it is..." is..."

"d.a.m.n you, upfluxer, we didn't come all this way to cower." And with a convulsive movement he grabbed the arrow and twisted it.

The device clicked through a quarter of a turn.

Dura flinched, wrapping her arms around her body. Even Hork could not help but wince as the arrow came to rest, pointing to the dark gray quadrant of the scale band. Then he exhaled heavily. "See? No harm done... In fact, nothing seems to have happened at all. And..."

"No." She shook her head. "You're wrong." She pointed. "Look..."

Hork twisted in the seat.

The walls of the chamber had turned transparent.

Bzya was dozing, hands loosely wrapped around the Bell's axial support pole, when the blue flashes started.

He snapped awake.

This had been a long, fruitless dive, and he had been looking forward to home, to breaking some beercake with Jool. But now something was wrong.

He scanned quickly around the cabin. Hosch, his only companion on this trip, was awake and alert; they shared a brief, interrogative glance. Bzya placed his hands gently on the polished, worn wood of the support pole. No unusual vibration. He listened to the steady hum of the great Corestuff hoops which bound about the hull of the Bell; the sound was an even thrumming, telling him that the current from the City still flowed down the cables as steadily as ever, throwing a magnetic cloak around their frail ship. He looked through the nearest of the Bell's three small windows. The Air outside - if it could be graced with the name, this far down - was a murky yellow, but bright enough to tell him that they were somewhere near the top of the underMantle. He could even see the shadow of the Spine; they were still close to its lower tip, not much more than a meter below the City...

There. Another of the blinding blue flashes, just beyond the window. It was electron-gas blue and it seemed to surround the ship; shafts of blue light shone briefly through the small round windows into the cabin. Another of the blinding blue flashes, just beyond the window. It was electron-gas blue and it seemed to surround the ship; shafts of blue light shone briefly through the small round windows into the cabin.

The Bell lurched.

Hosch wrapped his thin hands around the support pole. "Why aren't we dead?"

It was a good question. Clouds of electron gas around a Bell usually meant current surges in the Corestuff hoops. Maybe the cable from the Harbor was fraying, or a hoop failing. But if that was so the Bell's field would fail almost immediately. The Bell should have imploded by now.

"The current supply is still steady," Bzya said. "Listen."

They both held their breath, and looked into the Air; Hosch adopted the empty-eyed expression of a man trying to concentrate on hearing.

Another flash. This time the Bell actually rocked in the soupy underMantle, and Bzya, clinging tightly to the pole, was swung around like a sack. He pulled himself closer to the pole and wrapped his legs around it.

The supervisor's breath stank of meat and old beercake. "Okay," he said. "We know the Harbor supply is steady. What's causing the flashes?"

"There have to be current surges in the Corestuff hoops."

"If the City supply is steady that's impossible."

Bzya shook his head, thinking hard. "No, not impossible; the surges are just caused by something else."

Hosch's mouth pursed. "Oh. "Oh. Changes in the Magfield. Right." Changes in the Magfield. Right."

The Bell wasn't malfunctioning; the Magfield itself was betraying them. the Magfield itself was betraying them. The Magfield had become unstable, and it was inducing washes of charge flow in their protective hoops and dragging them away from their upward path to home. The Magfield had become unstable, and it was inducing washes of charge flow in their protective hoops and dragging them away from their upward path to home.

"What's causing the Magfield to vary?" Bzya asked. "Another Glitch?"

Hosch shrugged. "Hardly matters, does it? We're not going to live to find out."

There was an upward jolt, this time without the accompanying blue flash.

Bzya grasped the pole. "Feel that? That was the Harbor. They're pulling us up. We're not dead yet. They're trying to..."

And then the blue light came again, and this time stayed bright. Bzya felt the writhing Magfield haul at his stomach and the fibers of his body, even as it tore at the Bell itself.

Electron gas sparked from his own fingertips in streamers. It was really quite beautiful, he thought absently.

The Bell was hurled sideways, away from the Spine. Bzya's hands were torn from the support pole. The Bell's curving wall came up, like a huge cupped palm, to meet him. His face rammed into a window, hard. His body bent backward as it crammed itself into the tight inner curve of the wall. The structure of the Bell shuddered and groaned, and there was a distant, singing sound above him. That was the cables breaking, he thought through his pain. He felt oddly pleased at his own cleverness at such a deduction.

The walls wrenched, settled; the Bell rolled.

He fell into darkness.

Beyond the transparent walls, huge, ghostly buildings hovered over the humans.

The third chamber was immense, sufficient to enclose a million Parz Cities. The walls - made of the usual gray material, it seemed - were so far away as to be distant, geometric abstractions. Maybe this strange place was a series of nested tetrahedra, going on to infinity...

She Waved to Hork and reached out for him, blindly; still in the chair, he took her hands, and although his grip was strong she could feel the slick of fear on his palms. For a heartbeat she felt an echo of the pa.s.sion they'd briefly found, in flight from terror during the journey.

The transparent structures hovered around them like congealed Air. They were translucent boxes hundreds of thousands of mansheights tall. And within some of the buildings more devices could be seen, embedded; the inner structures were ghosts within ghosts, gray on gray.

The tetrahedral box containing the "Pig," the solid little chair, Hork and Dura themselves, were like specks of wood adrift in some mottled fluid. In fact, she realized, the whole of the tetrahedron they occupied was embedded inside inside one of the huge buildings; its gray lines sectioned off the s.p.a.ce around them, and she looked out through its spectral flesh. one of the huge buildings; its gray lines sectioned off the s.p.a.ce around them, and she looked out through its spectral flesh.

"Why do you suppose we can't see these things clearly? And I wonder what their purpose is. Do you think..."

Hork was peering up at the "building" they were embedded in. He stared into its corners and at its misty protuberances, and then glanced down quickly at the chair he sat in.

"What's wrong?"

"The ghost-building we're inside. Look at it... It has the same shape as this chair." The gray light of the translucent forms pooled in his eyecups. "It's a hundred thousand times the size, and it's made of something as transparent as clearwood and thinner than Air... but nevertheless, it's an immense - spectral - chair. chair.

She lifted her head. Slowly she realized that Hork was right. This immense "building" - at least a meter tall - had a seat, a back; and there, so far above her it was difficult to see, were two arms, each with its control lever.

Hork grinned, his face animated. "And I think I know what it's all for. Watch this!"

He twisted his body. His chair swiveled in the Air.

She gasped, Waving away in alarm; but the chair came to rest, and no damage seemed to have been done. "What are you doing?"

"Don't you understand yet? Look up!"

She tilted her head back.

The other "chair" - the ghostly a.n.a.logue - had turned too, had turned too, swiveling to match Hork's lurch. swiveling to match Hork's lurch.

"See?" he crowed. "The chair is keyed to mine, somehow; whatever I make mine do, the big one must follow." Hork swung this way and that, laughing like a child with a toy. Dura watched the giant a.n.a.logue dance clumsily, aping Hork's movements like some huge pet. Presumably, she thought, when the device swiveled, its substance must be moving around her - through through her, in fact, like an unreasonable breeze. But she felt nothing - at least, no more than an inner chill which could as easily be caused by her awe and fear. her, in fact, like an unreasonable breeze. But she felt nothing - at least, no more than an inner chill which could as easily be caused by her awe and fear.

At last Hork tired of his games. "I can make it do whatever I want." He looked a little more thoughtful. "And so if I pull these levers..."

"No. We need to work this out, Hork." She looked up. "This - ghost, this City-sized artifact - is a seat big enough for a giant..."

"That's obvious. But..."

"But," she interrupted, "a giant of a certain form... a human-shaped giant, meters tall." She studied his face, waiting for him to reach the same conclusions.

"Meters... The Ur-humans." The Ur-humans."

She nodded. "Hork, I think the ghost-seat is an Ur-human device. I think we're in a little bubble of Air, floating inside an Ur-human room."

She tilted her head back on her neck, feeling the flesh at the top of her spine bunch under her skull, and looked up into a ghost-room which abruptly made sense.

They were inside inside a huge Ur-human chair. But there were other chairs - four of them, she counted, receding into mistiness, like a row of cities. The chairs were placed before a long, flat surface, and she caught hints of a complex structure beneath and behind that surface. Perhaps that was some form of control panel. Looking further out, the tetrahedral structure surrounding all of this was a sketch drawn against fog. a huge Ur-human chair. But there were other chairs - four of them, she counted, receding into mistiness, like a row of cities. The chairs were placed before a long, flat surface, and she caught hints of a complex structure beneath and behind that surface. Perhaps that was some form of control panel. Looking further out, the tetrahedral structure surrounding all of this was a sketch drawn against fog.

Hork touched her arm. "Look over there." He pointed. On the side of the Ur-human room opposite the row of seats there was a bank of billowing gas - but that must be wrong, of course; she tried to forget her smallness, to see this through Ur-human eyes. It was a structure made up of something soft, pliable, piled up on a lower flat surface. It looked like a coc.o.o.n, laid flat.

Did the Ur-humans sleep? sleep?

Again Hork was pointing. "On top of that surface before the chairs. See? Instruments, built for giant hands."

Dura saw a cylinder longer than a Crust-tree trunk. Its end was sharp, protruding over the lip of the surface. Perhaps it was a stylus, as she'd seen Deni Maxx use in the Hospital. She tried to imagine the hand that could grasp a tree trunk and use it to write notes... Beside the "stylus" there was another cylinder, but this was set upright. It seemed to be hollow - the cylinder was transparent to Dura's eyes, and she could make out a structure of thick walls surrounding an empty s.p.a.ce - and there was no upper surface.

She frowned and pointed out the second cylinder to Hork. "What do you think that is? It looks like a fortress. Perhaps the Ur-humans needed to shelter - perhaps they came under attack..."

He was laughing at her, not unkindly. "No, Dura. You've lost the scale. Look at it again. It's maybe - what? - ten thousand mansheights tall?"

"Ten times as big as your glorious Parz City."

"Maybe, but that's still only ten centimeters or so. Dura, the Ur-humans were meters meters tall. The tall. The hand hand of an Ur-human could have engulfed that cylinder." He was watching her slyly. "Do you see it yet? Dura, that's a food vessel. A cup." of an Ur-human could have engulfed that cylinder." He was watching her slyly. "Do you see it yet? Dura, that's a food vessel. A cup."

She stared. A cup, large enough to hold a dozen Parz Cities?

She tried to keep thinking. "Well," she said, "then it's a d.a.m.n odd cup. All the food would float out of the top. Wouldn't it?"

Hork nodded grudgingly. "You'd think so." He sighed. "But then, there are many things about the Ur-humans we can't understand."

She imagined this little box of Mantle-stuff from the outside. "It's as if they created this inner chamber, around the wormhole Interface, as an ornament. A little section of the Star, so they could study Human Beings. We would look like toys to them," she murmured. "Less than toys; little animals, perhaps below the level of visibility." She looked at her hand. "They were a hundred thousand times taller than us; even the 'Pig' would have been no more than a mote in the palm of an Ur-human child..." She shivered. "Do you think any of them are still here?" She imagined a giant Ur-form floating in through some half-seen door, a face wider than a day's journey billowing down toward her...

"No," Hork said briskly. "No, I don't. They've gone."

She frowned. "How do you know?"

He grinned. "For one thing, that's what your precious legends tell us. But the clincher is this seat." He patted its arms. "The Ur-humans set up this place so that we we could work their machines. If I move the chair I can mimic anything an Ur-human could have done... Dura, they have made me as powerful as any of them. Do you see?" He probed at the unyielding surface of the chair. "If we had the wit we could operate other devices." He looked around the ghostly chamber greedily. "There must be wonders here. Weapons we've never dreamed of." could work their machines. If I move the chair I can mimic anything an Ur-human could have done... Dura, they have made me as powerful as any of them. Do you see?" He probed at the unyielding surface of the chair. "If we had the wit we could operate other devices." He looked around the ghostly chamber greedily. "There must be wonders here. Weapons we've never dreamed of."

The Ur-humans had meant Star people to come here, to work the devices they left behind, maybe when the Glitches got too bad. Perhaps there was something they were meant to do now... But what?

"Your arrow device doesn't have an a.n.a.logue, in the Ur-human chair," she said slowly, pointing up. "See? So the arrow-thing must be something meant for us alone. Maybe to help us see what's going on." She frowned. "It only turned one quarter. What if you turned it again?"

"Only one way to find out."

He reached for the arrow.

At first he turned it back toward the darkest sector of the scale. Rea.s.suringly the walls of smooth gray material congealed around them, shutting out the chamber of the Ur-humans. And when Hork twisted the arrow the other way the walls vanished, to reveal the vast devices.

"All right," he said. "Going from the black to the dark gray allows us to see a little more. A little further. And what if I turn it another quarter, to the light gray?"

Dura shrank back despite herself. "Just turn it," she said hoa.r.s.ely.

Confidently he twisted the arrow to the third of the four quarters.

Light seemed to bleed out of the Air.

The devices of the Ur-humans, the walls of their ghostly chamber, became still more translucent. And there was darkness beyond those distant walls, darkness which settled on the two humans, huddled as they were within layers of immensity.

Points of light hung in that darkness.

Dura twisted in the Air, staring around. "I don't understand. I can't see the walls of the next chamber. And what are those lights?"

"There are no more walls," Hork said gently. "Don't you see? No more chambers. We're looking out into s.p.a.ce, We're looking out into s.p.a.ce, Dura, at volumes even the Ur-humans couldn't enclose." Dura, at volumes even the Ur-humans couldn't enclose."

She found her hand creeping into his. "And those lights..."

"You know what they are, Dura. They're stars. stars. Stars and planets." Stars and planets."

"Wake up, Bzya, you useless a.s.shole."

Hosch was slapping him. Bzya shook his head, blinking to clear his eye. He was surprised to be alive; the Bell should have imploded.

His bad eyecup blazed with pain. He raised a tentative fingertip to it to find the cup filled with sticky matter. His back ached, right at the base, where it had been bent backward against the curve of the Bell.

"So we're not dead," he said.

Hosch grinned, his thin face drawn tight with fear. "We aren't that deep in the underMantle. We can't be, or the Bell would have collapsed already." He was kicking at the rim of the hatch frame, trying to splinter it with his heel.