you owe us
your life; that may be a small enough gift, and one quickly withdrawn. I
say only that you have no escape from us. We have your name, and the
true symbol is the thing, as you should know. We also have cuttings from
your hair and your beard; we have the parings of your nails, five cubic
centimeters of your spinal fluid and a scraping from your liver. We have
your body through those, nor can you take it out of our reach. Your name
gives us your soul." He looked at Hanson piercingly. "Shall I tell you
what it would be like for your soul to live in the muck of a swamp in a
mandrake root?"

Dave shook his head. "I guess not. I--look, Ser Perth. I don't know what
you're talking about. How can I go along with you when I'm in the dark?
Start at the beginning, will you? I was killed; all right, if you say I
was, I was. You brought me to life again with a mandrake root and
spells; you can do anything you want with me. I admit it; right now,
I'll admit anything you want me to, because you know what's going on and
I don't. But what's all this business of the sky falling? If it is and
can be falling, what's the difference? If there is a difference, why
should I be able to do anything about it?"

"Ignorance!" Ser Perth murmured to himself. He sighed heavily. "Always
ignorance. Well, then, listen." He sat down on the corner of the desk
and took out a cigarette. At least it looked like a cigarette. He
snapped his fingers and lighted it from a little flame that sprang up,
blowing clouds of bright green smoke from his mouth. The smoke hung
lazily, drifting into vague patterns and then began to coalesce into a
green houri without costume. He swatted at it negligently.

"Dratted sylphs. There's no controlling the elementals properly any
more." He didn't seem too displeased, however, as he watched the thing
dance off. Then he sobered.

"In your world, Dave Hanson, you were versed in the engineering
arts--you more than most. That you should be so ignorant, though you
were considered brilliant is a sad commentary on your world. But no
matter. Perhaps you can at least learn quickly still. Even you must have
had some idea of the composition of the sky?"

Dave frowned as he tried to answer. "Well, I suppose the atmosphere is
oxygen and nitrogen, mostly; then there's the ionosphere and the ozone
layer. As I remember, the color of the sky is due to the scattering of
light--light rays being diffracted in the air."

"Beyond the ai