Sather Karf smiled approvingly. "The theory of resonance, I see. Unreliable generally. More of an art than a science. But you show promise of remarkable natural ability to apply it." "You know about it?" Dave had assumed that it was completely outside their experience and procedures. "We _knew_ it. But when more advanced techniques took over, most of us forgot it. The syllables resonate in a sound pattern with your world, to which you also still resonate. It won't work for you with anything from this world, nor will anything work thus for us from yours. We had different syllables, of course, for use here." Sather Karf considered it. "But if you can control it and bring in one of your computers or the parts for one--" Sixteen tries later, Dave was cursing as he stared at a pile of useless items. He'd gotten transistors at first. Then he lost control with too much tension or fatigue and began getting a bunch of assorted junk, such as old 201-A tubes, a transit, a crystal vase and resistors. But the chief trouble was that he couldn't secure working batteries. He had managed a few, but all were dead. "Like the soul, electrical charges will not transfer," Sather Karf agreed sadly. "I should have told you that." There was no electricity here with which to power anything, and their spells could not be made to work now. Even if he could build a computer out of what was obtainable, there would be no way to power it. Overhead, the sky shattered with a roar, and another piece fell, tearing downwards toward the city. Sersa Garm stared upwards in horror. "Mars!" he croaked. "Mars has fallen. Now can there be no conjunction ever!" He tautened and his body rose slowly from the ground. A scream ripped from his lips and faded away as he began rushing upwards with increasing speed. He passed but of their sight, straight toward the new hole in the sky. IX In the hours that followed, Dave's vague plans changed a dozen times as he found each idea unworkable. His emotional balance was also erratic--though that was natural, since the stars were completely berserk in what was left of the sky. He seemed to fluctuate between bitter sureness of doom and a stupidly optimistic belief that something could be done to avert that doom. But whatever his mood, he went on working and scheming furiously. Maybe it was the desperate need to keep himself occupied that drove him, or perhaps it was the pleading he saw in the eyes around him. In the end, determination conquered his pessimism. Somewhere in the combination of the science he had learned in his own world and the technique of magic that applied here there had to be an answer--or a means to hold back the end of the world until an answer could be found. The biggest problem was the number of factors with which he had to deal. There were seven planets and the sun, and three thousand fixed stars. All had to be ordered in their courses, and the sky had to be complete in his calculations.