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."