here," he said.

"Then why didn't you say so?" she asked sharply. She let out a cry and a
raven came flying in. She whispered something to it, frowned, and then
ordered it off. "There's no surface transportation available, and all
the local rocs are in use. Well, we'll have to make do with what we
have."

She darted for the outer office, rummaged in a cabinet, and came back
with a medium-sized rug of worn but gaudy design. Bad imitation Sarouk,
Dave guessed. She tossed it onto the largest cleared space, gobbled
some outlandish noises, and dropped onto it, squatting near one end.
Behind her, the dull clod picked up the sample of sky and fell to his
face on the rug. At her vehement signal, Dave squatted down beside her,
not daring to believe what he was beginning to guess.

The carpet lifted uncertainly. It seemed to protest at the unbalanced
weight of the sky piece. She made the sounds again, and it rose
reluctantly, curling up at the front, like a crazy toboggan. It moved
slowly, but with increasing speed, sailed out of the office through the
window and began gaining altitude. They went soaring over the city at
about thirty miles an hour, heading toward what seemed to be barren land
beyond. "Sometimes they fail now," she told him. "But so far, only if
the words are improperly pronounced."

He gulped and looked gingerly over at the city below. As he did, she
gasped. He heard a great tearing sound of thunder. In the sky, a small
hole appeared. There was a scream of displaced air, and something went
zipping downwards in front of them, setting up a wind that bounced the
carpet about crazily. Dave glanced over the edge again to see one of the
tall buildings crumple under the impact. The three top stories were
ripped to shreds. Then the whole building began to change. It slowly
blossomed into a huge cloud of pink gas that rifted away, to show people
and objects dropping like stones to the ground below. Nema sighed and
turned her eyes away.

"But--it's ridiculous!" Dave protested. "We heard the rip and less than
five seconds later, that piece fell. If your sky is even twenty miles
above us, it would take longer than that to fall."

"It's a thousand miles up," she told him. "And sky has no inertia until
it is contaminated by contact with the ground. It took longer than
usual for that piece to fall." She sighed. "It gets worse. Look at the
signs. That break has disturbed the planets. We're moving retrograde,
back to our p