Dave stared up at the mottled dome above him and at the dull clod--certainly a mandrake--who was still carrying the sample. With all this preparation and a time limit, he couldn't even afford to stall. He'd never fully understood why some plastics melted and others turned hard when heated, but he had to find what was wrong with the dome above and how to fix it. And maybe the time limit could be stretched a little, once he came up with the answer. Maybe. He'd worry about that after he worried about the first steps. Sersa Garm proved to be a glum, fat young man, overly aware of his importance in training for serhood. He led Dave through the big tent, taking pride in the large drafting section--under the obvious belief that it was used for designing spells. Maybe it could have been useful for that if there had been a single man who knew anything about draftsmanship. There were four engineers, supposedly. One, who had died falling off a bridge while drunk, was curing himself of the shock by remaining dead drunk. One had been a chemical engineer specializing in making yeast and dried soya meal into breakfast cereals. Another knew all about dredging canals and the last one was an electronics engineer--a field in which Dave was far more competent. He dismissed them. Whatever had been done to them--or perhaps the absence of a true soul, whatever that was--left them rigidly bound to their past ideas and totally incapable of doing more than following orders by routine now. Even Sersa Garm was more useful. That young man could offer little information, however. The sky, he explained pompously, was a great mystery that only an adept might communicate to another. He meant that he didn't know about it, Dave gathered. Everything, it turned out, was either a mystery or a rumor. He also had a habit of sucking his thumb when pressed too hard for details. "But you must have heard some guesses about what started the cracks in the sky?" Dave suggested. "Oh, indeed, that is common knowledge," Sersa Garm admitted. He changed thumbs while he considered. "'Twas an experiment most noble, but through mischance going sadly awry. A great Sather made the sun remain in one place too long, and the heat became too great. It was like the Classic experiment--" "How hot is your sun?" There was a long pause. Then Sather Germ shrugged. "'Tis a great mystery. Suffice to say it has no true heat, but does send forth an activating principle against the phlogiston layer, which being excited grows vengeful against the air ... but you have not the training to understand." "Okay, so they didn't tell you, if they knew." Dave stared up at the sun, trying to guess. The light looked about like what he was used to, where the sky was still whole. North light still was like what a color photographer would consider 5500 deg. Kelvin, so the sun must be pretty hot. Hot enough to melt anything he knew about. "What's the melting point of this sky material?"