he fourth was a massive structure of rose
granite, beetling above us, a monstrous shape in the dimness, throwing a
shadow half across the paved space. We raced across the shadow toward
the nearest doorway, flattened against it, listening for life inside.
Carna worked on the catch of the door, after a second slid the door
aside slowly, carefully. Inside I could see a shimmering smoothness,
round, higher than my head, a top-shaped object. I guessed that this was
the ship she meant to steal from the Schrees. Suddenly the door she was
sliding open scraped, and emitted a shrill, high-pitched sound. I did
not know if it was an alarm activated by the opening door or just rust
on the rails and wheels of the door mechanism. Carna cried:

"Hurry, get into the ship, we must take off at once. They will come;
they must have heard that sound!"

I ducked into the darkness, circled the bulging shape, looking for an
opening. Smooth, there seemed no way I could find.

"Here it is, help me open it," Carna panted behind me.

I leaped to her side. She was twisting at an inset handle around which
faint lines indicated the door edge. I pulled her aside, took hold of
the handle, twisted hard. It bent, then gave, and the door swung easily
open in my hands. We tumbled in. Carna raced through the first chamber,
and even as I got the door closed, the floor lifted under my feet
easily, drifted out of the wide doorway, shot upward so quickly I was
thrown to the floor. I lay there, the increasing acceleration pressing
me hard against the cool metal. After a time I struggled up, made my way
to the woman's side.

Ahead was the moonlit range of mountains. Carna was setting a course
straight along the ridge of them, heading southward.

"How far will this thing fly?" I asked.

"It will fly around your world many times, if I want it to."

"What kind of fuel does it use?" I asked incredulously.

"I don't know what that is. It uses a substance we call Ziss. It is a
good fuel."

"It must be!"

I looked back along the ridge of the mountain's top toward the valley we
had left. We were in a bubble on the top of the flat, circular ship; one
could see in any direction. Back there a series of glowing round shapes
shot upward, came after us in a long curve that would bring them ahead
of us on our course. Carna changed her course to parallel the pursuit,
and they changed again, to intercept her new direction. Again she
changed, circling farther west.