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 previous position, out of Sagittarius! Now we'll go back to
the character we had before--and just when I was getting used to the
change."

He jerked his eyes off the raw patch of emptiness in the sky, where a
few stars seemed to be vanishing. "Your character? Isn't anything stable