He had always known that the arch was an optical illusion; only now did it really hit home. He was rising up the inside wall of a ring two thousand kilometers in diameter and five hundred wide. The walls cupped an ocean of atmosphere and at its bottom lay the carefully sculpted landscape of whole continents.

Was Raven's people really just another carefully crafted segment of coronal shell, five or ten meters thick with vacuum below it? The hills he had climbed as a child, hollow and metal? Of course they were; and it shouldn't matter. He had known this all along, he had known it, surely he had. What did it matter to the hawk and the otter that their world was artificial? It shouldn't matter to him, either.

He fought back tears and turned away.

No one had spoken since they began this ascent. Time seemed stretched, as if each second was an hour. But if Qiingi glanced at the wall behind him, it fell past with an uncanny speed.

One of the boxes burst open in a white cloud of ice. Aaron closed it again by sitting on it. "We're nearly at vacuum," he said. "A real workout for our angels." Nobody laughed.

Qiingi thought about what Livia had said. He had believed that her strength came from a belief that the world was wider than any one manifold. Because she knew that, she could put her own world away when needed, and trade her ghahlanda for that of another place. So Qiingi had believed.

He still believed that. But she didn't.

"There," said Aaron. "Our destination." He pointed up and to one side. Qiingi followed his gaze.

Something perched on the very edge of the wall top, which was now only a few kilometers overhead. Unfamiliar with such things, it took him a while to realize that the tiny square object was a house.

Livia stood, her misery temporarily forgotten. "Aaron! That can't be real. Who would be insane enough ... T

Aaron shrugged. "We never found out. Maybe Raven himself. I learned about the place from my uncle. He said he found it thirty years ago. It had been abandoned a long time by then. But it's not the only building on the top of the walls, Livia. There's a whole city on the north side; and there's lots of other places, some like this, some totally alien looking. You can find them with a good telescope, they're usually at the top of the coronal's built-in elevators — like the one we're riding."

They stood watching as the top of the wall approached. The house blazed brilliant against the black sky; it was lit not from above, but from the side. The vertical surface of the wall below it also glowed, fading gradually over hundreds of meters. "See the way it shines," said Aaron. "That house is the first thing you've ever seen that's lit directly by the sun." Qiingi looked up; the suns he had grown up knowing as the most constant of things were now faint curved slits in blackness. For the first time in full daylight he could see the edges of the vast oval mirror that slowly spun in the open center of the coronal ring. Teven Coronal rotated at right angles to the sun, and the oval mirror directed light down onto the ring's inner surface. The mirror itself turned, slower than Teven, to create a twenty-four-hour day. From here the mirror's edge looked crisp and clear, as if it were only meters away. It was at least two hundred kilometers above him.

Then they rose onto the glowing section of wall, and sunlight burst on Qiingi from the side. He looked out over the well of light that was Teven, and saw the true sun of humanity rising slowly over the north wall of the world. His first real sunrise. It declared his entire previous existence a lie.

He couldn't think; couldn't even breathe for a few moments. With a start he realized they had stopped rising. Aaron was opening the metal gate of the cage, his expression resolute.

"I'm glad you convinced us to do this, Livia," Aaron said. 'Td forgotten what it was like up here. From here you can see the truth: 3340 may be conquering every manifold in the coronal, but now it's clear just how small mat conquest really is."

The three-story Tudor-style chalet sat on the very edge of the cliff, a kilometer from the elevator. The first thing Livia noticed was that it wasn't alone up here; the top of the wall was littered with junk — opened boxes, broken machines of various technology levels, uprooted and dried plants. They were scattered in a broad arc around the house. Looking beyond them, she saw that the dark surface was about two hundred meters wide, north to south. Its clean edges converged to infinity east and west, with the swirled white-and-blue of the coronal's lands to die north side of it, and utter blackness to the south.

Aaron was hauling some boxes in the direction of the house. Listlessly, she went to join him. "I can't see stars," she commented.

"Too dim to be seen in die day," he muttered. "Damn!" He'd grabbed a crate and frost-burned the palm of his hand through the material of his angel. "Come on, we have to hurry with this stuff."

"But I don't understand what we're doing," she said. "Are we hiding here?"

"We probably could, but for how long?" He shook his head. "No, look: the house isn't attached to anything. It's just sitting on the surface. That's because this stuff," he stamped, "is too hard to be drilled or punctured by normal means. It's woven fullerene — carbon nanotubes — like the whole coronal. Whoever built the house just hauled it up and pushed it to that spot. We're going to push it ourselves, only in that direction." He jabbed a thumb at the fathomless black that ate half the vista.

Qiingi had been dutifully dragging a sack of assembler spores. Now he stopped and peered at Aaron. "Is your xhants ill, Aaron? You are not making sense."

"Sure I am," he said, lifting the crate more carefully. "The house is airtight. It has its own heat source, which we just have to fire up. I've brought supplies ... you have to get over the idea that we'd be falling if we went over that edge, Wordweaver. If you jump over that edge," he pointed at the bright side, "you'll fall fifty kilometers and splat on the mountains below. But if you go that way," he nodded at the blackness, "you're not falling. You're traveling."

Livia half listened as they brought the supplies in through the house's airtight foyer, which Aaron called an "airlock." The coronals, he said, were colossal spinning rings and anything dropped off the edge of one, if it was dropped at the right time, would travel through space in a straight line until it gently tapped the underside of the next coronal in line. "And underneath the coronals," said Aaron, "there are landing pads. Those are automatic; they won't let us miss."

Teven Coronal was but one of many. Aaron had used his telescopes to verify that a chain of them led millions of kilometers into the distance — past the heaven-sized pillars of luminous gas that obscured most of the night sky. The chain might lead all the way to the place where the founders had come from. History spoke of a universe outside of Teven holding trillions of people. But crucial details of that wider world had been lost — obscured, she now realized, by Ellis and the other founders.

To people confident of their permanent isolation, such a sacrifice must have made sense; the founders had wanted each manifold to be able to craft its own origin story, consistent with its values. But once that isolation was disturbed, the folly of the plan became obvious.

They knew nothing of where they were going. So either the coronal next door would have its own civilization and be willing to help them; or it was the very home of 3340. In which case this journey was in vain.

The airlock opened and Livia stepped into the front hall of the house. It was shocking in its normality: the floor was pallasite tile, illuminated from below, and an ordinary side table held a green vase containing withered flowers. Faded portraits hung on the walls. She wandered in a daze into a rustic living room with a beamed ceiling. Her feet sank into deep white pile carpet. A long couch and two leather armchairs faced a stone mantelpiece with satyrs carved in it. Above the mantel was an excellent painting of the Southwall mountains. A burl oak writing table sat in one corner, an empty rosewood china cabinet in another.