Why should randomness upset her so? Because, she realized slowly, there were no vortex lines here, no neat Crust ceiling or Sea floor. All her life had been spent in a ruled-off sky — a sky where any hint of irregularity was so unusual as to be a sign of deadly danger.

But there were no lines here, no reassuring anchor-points for her mind.

"Are you all right?" Hork sounded calmer than she was, but his eyecups were wide and his nostrils flared, glowing like nuclear-burning wood above his bush of beard.

"No. Not really. I'm not sure I can accept all this."

"I know. I know." Hork lifted up his face. In the starlight the intrinsic coarseness of his features seemed to melt away, leaving a calm, almost elegiac expression. He waved a hand across the sky. "Look at the stars. Look how their brightness varies... But what if that variation is an illusion? Have you thought about that? What if all the stars are about as bright as each other?"

Her mind — as usual — plodded slowly behind his flight of logic. If the stars were all the same intrinsic brightness, then some of them would have to be further away. Much further away.

She sighed. No, damn it. She hadn't thought of that.

Somehow she'd been picturing the starry Ur-universe as a shell around her — like the Crust, though much further away. But it wasn't like that; she was surrounded by an unbounded sky throughout which the stars — themselves worlds — were scattered like spin-spider eggs.

The universe ballooned around her, reducing her to a meaningless mote, a spark of awareness. It was oppressive, beyond her imagination; she cried out, covering her face in her hands.

Hork sounded uncomfortable. "Take it easy."

Irritation burrowed through her awe. "Oh, sure. And you're quite calm, I suppose. Sorry to embarrass you..."

"Give me a break."

She turned away from him, striving for calm. "I wish I knew what is an appropriate response to all this — to be here in this ancient place, to be seeing through the eyes of the Ur-humans..."

"Well, not quite," Hork said gently. "Remember there are still walls around us, which must somehow be helping us to see. The Ur-humans didn't see things the same way we do. Ask Muub about it when we get back... We 'see' by sound waves which are transmitted through the Air." He waved a hand. "But beyond this little bubble, there isn't any Air. The Ur-humans didn't live in Air, in fact. And they 'saw' by focusing beams of photons, which..."

She wrinkled her nose. "They could smell the stars?"

"Of course not," he snapped. "In Air, photons can travel only slowly, diffusing. So we use them to smell. And we 'hear' temperature fluctuations.

"In empty space, it's different. Phonons can't travel at all — so we would be blind. But photons travel immensely fast. So the Ur-humans could have 'seen' photons... Anyway, that's Muub's theory."