ay, a stratosphere roc
crashed head-on into a fragment of the sky and was killed with all its
passengers. Worst of all, the Science of Magic suffers. Because the
stars are fixed on the dome of the sky. With the crumbling of that dome,
the course of the stars has been corrupted. It's pitiful magic that can
be worked without regard to the conjunctions of the planets; but it is
all the magic that is left to us. When Mars trines Neptune, the Medical
Art is weak; even while we were conjuring you, the trine occurred. It
almost cost your life. And it should not have occurred for another seven
days."

There was silence, while Ser Perth let Dave consider it. But it was too
much to accept at once, and Dave's mind was a treadmill. He'd agreed to
admit anything, but some of this was such complete nonsense that his
mind rejected it automatically. Yet he was sure Ser Perth was serious;
there was no humor on the face of the prissy thin-mustached man before
him. Nor had the Sather Karf considered it a joke, he was sure. He had a
sudden vision of the latter strangling two men from a distance of thirty
feet without touching them. That couldn't happen in a sane world,
either.

Dave asked weakly, "Could I have a drink?"

"With a sylph around?" Ser Perth grimaced. "You wouldn't have a chance.
Now, is all clear to you, Dave Hanson?"

"Sure. Except for one thing. What am I supposed to do?"

"Repair our sky. It should not be too difficult for a man of your
reputation. You built a wall across a continent high and strong enough
to change the air currents and affect all your weather--and that in the
coldest, meanest country in your world. You come down to us as one of
the greatest engineers of history, Dave Hanson, so great that your fame
has penetrated even to our world, through the viewing pools of our
wisest historians. There is a shrine and monument in your world. 'Dave
Hanson, to whom nothing was impossible.' Well, we have a nearly
impossible task: a task of engineering and building. If our Science of
Magic could be relied upon--but it cannot; it never can be, until the
sky is fixed. We have the word of history: no task is impossible to Dave
Hanson."

Dave looked at the smug face and a slow grin crept over his own, in
spite of himself. "Ser Perth, I'm afraid you've made a slight mistake."

"We don't make mistakes in such matters. You're Dave Hanson," Ser Perth
said flatly. "Of all the powers of the Science, the greatest lies in the