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 passion 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 one of the huge buildings; its gray lines sectioned off the space 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.

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 analogue — had turned too, swiveling to match Hork's lurch.