"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."
Ser Perth shrugged. "Then why make me say it again? This Fort was right. At least one intelligent man lived in your world, I'm pleased to know. The sky is a dome holding the sun, the stars and the wandering planets. The problem is that the dome is cracking like a great, smashed eggshell."
"What's beyond the dome?"
Ser Perth shuddered slightly. "My greatest wish is that I die before I learn. In your world, had you discovered that there were such things as elements? That is, basic substances which in combination produce — "
"Of course," Dave interrupted.
"Good. Then of the four elements — " Dave gulped, but kept silent, " — of the four elements the universe is built. Some things are composed of a single element; some of two, some of three. The proportions vary and the humors and spirits change but all things are composed of the elements. And only the sky is composed of all four elements — of earth, of water, of fire and of air — in equal proportions. One part each, lending each its own essential quality to the mixture, so that the sky is solid as earth, radiant as fire, formless as water, insubstantial as air. And the sky is cracking and falling, as you have seen for yourself. The effects are already being felt. Gamma radiation is flooding through the gaps; the quick-breeding viruses are mutating through half the world, faster than the Medical Art can control them, so that millions of us are sneezing and choking — and dying, too, for lack of antibiotics and proper care. Air travel is a perilous thing; just today, 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 true name. We evoked you by the name of Dave Hanson. You are Dave Hanson, therefore."
"Don't try to deceive us," Nema suggested. Her voice was troubled. "Pray rather that we never have reason to doubt you. Otherwise the wisest of the Satheri would spend their remaining time in planning something unthinkable for you."
Ser Perth nodded vigorous assent. Then he motioned to the office. "Nema will show you to your quarters later. Use this until you leave. I have to report back."
Dave stared after him until he was gone, and then around at the office. He went to the window and stared upwards at the crazy patchwork of the sky. For all he knew, in such a sky there might be cracks. In fact, as he looked, he could make out a rift, and beyond that a ... hole ... a small patch where there was no color, and yet the sky there was not black. There were no stars there, though points of light were clustered around the edges, apparently retreating.
All he had to do was to repair the sky. Shades of Chicken Little!
Maybe to David Arnold Hanson, the famed engineer, no task was impossible. But quite a few things were impossible to that engineer's obscure and unimportant nephew, the computer technician and generally undistinguished man who had been christened Dave. They'd gotten the right man for the name, all right. But the wrong man for the job.
Dave Hanson could repair anything that contained electrical circuits or ran on tiny jeweled bearings, but he could handle almost nothing else. It wasn't stupidity or incapacity to learn, but simply that he had never been subjected to the discipline of construction engineering. Even on the project, while working with his uncle, he had seen little of what went on, and hadn't really understood that, except when it produced data that he could feed into his computer. He couldn't drive a nail in the wall to hang a picture or patch a hole in the plaster.
But it seemed that he'd better put on a good show of trying if he wanted to continue enjoying good health.
"I suppose you've got a sample of the sky that's fallen?" he asked Nema. "And what the heck are you doing here, anyhow? I thought you were a nurse."
She frowned at him, but went to a corner where a small ball of some clear crystalline substance stood. She muttered into it, while a surly face stared out. Then she turned back to him, nodding. "They are sending some of the sky to you. As to my being a nurse, of course I am. All student magicians take up the Medical Art for a time. Surely one so skilled can also be a secretary, even to the great Dave Hanson? As to why I'm here — " She dropped her eyes, frowning, while a touch of added color reached her cheeks. "In the sleep spell I used, I invoked that you should be well and true. But I'm only a bachelor in magic, not even a master, and I slipped. I phrased it that I wanted you well and true. Hence, well and truly do I want you."
"Huh?" He stared at her, watching the blush deepen. "You mean — ?"
"Take care! First you should know that I am proscribed as a duly registered virgin. And in this time of need, the magic of my blood must not be profaned." She twisted sidewise, and then turned toward the door, avoiding him. Before she reached it, the door opened to show a dull clod, entirely naked, holding up a heavy weight of nothing.
"Your sample of sky," she said as the clod labored over to the desk and dropped nothing with a dull clank. The desk top dented slightly.
Dave could clearly see that nothing was on the desk. But if nothing was a vacuum, this was an extremely hard and heavy one. It seemed to be about twelve inches on a side, in its rough shape, and must have weighed two hundred pounds. He tapped it, and it rang. Inside it, a tiny point of light danced frantically back and forth.
"A star," she said sadly.
"I'm