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 air," Ser Perth said impatiently. "The sky itself!" "Oh--space. We were just getting out there with manned ships. Mostly vacuum, of course. Of course, we're still in the solar atmosphere, even there, with the Van Allen belts and such things. Then there are the stars, like our sun, but much more distant. The planets and the moon--" "Ignorance was bad enough," Ser Perth interrupted in amazement. He stared at Dave, shaking his head in disgust. "You obviously come from a culture of even more superstition than ignorance. Dave Hanson, the sky is no such thing. Put aside the myths you heard as a child. The sky is a solid sphere that surrounds Earth. The stars are no more like the sun than the glow of my cigarette is like a forest fire. They are lights on the inside of the sphere, moving in patterns of the Star Art, nearer to us than the hot lands to the south." "Fort," Dave said. "Charles Fort said that in a book."