For convenience of installation in the body, Dimanche was packaged in two units. The larger package was usually surgeried into the abdomen. The small one, containing the speaker, was attached to the skull just behind the ear. It worked by bone conduction, allowing silent communication between operator and instrument. A real convenience. It wasn't enough to know this, as Cassal did. He'd talked to the company experts, had seen the symbolical drawings, the plans for an improved version. He needed something better than the best though, that had been planned. The drawback was this: _Dimanche was powered directly by the nervous system of the body in which it was housed_. Against Murra Foray, he'd be over-matched. She was stronger than he physically, probably also in the production of nervous energy. One solution was to make available to the new instrument a larger fraction of the neural currents of the body. That was dangerous--a slight miscalculation and the user was dead. Yet he had to have an instrument that would overpower her. Cassal rubbed his eyes wearily. How could he find some way of supplying additional power? Abruptly, Cassal sat up. That was the way, of course--an auxiliary power pack that need not be surgeried into his body, extra power that he would use only in emergencies. Neuronics, Inc., had never done this, had never thought that such an instrument would ever be necessary. They didn't need to overpower their customers. They merely wanted advance information via subvocalized thoughts. It was easier for Cassal to conceive this idea than to engineer it. At the end of the first day, he knew it would be a slow process. Twice he postponed deadlines to the manufacturing concerns he'd engaged. He locked himself in his rooms and took Anti-Sleep against the doctor's vigorous protests. In one week he had the necessary drawings, crude but legible. An expert would have to make innumerable corrections, but the intent was plain. One week. During that time Murra Foray would be growing hourly more proficient in the use of Dimanche. * * * * * Cassal followed the neuronics expert groggily, seventy-two hours sleep still clogging his reactions. Not that he hadn't needed sleep after that week. The Godolphian showed him proudly through the shops, though he wasn't at all interested in their achievements. The only noteworthy aspect was the grand scale of their architecture. "We did it, though I don't think we'd have taken the job if we'd known how hard it was going to be," the neuronics expert chattered. "It works exactly as you specified. We had to make substitutions, of course, but you understand that was inevitable." He glanced anxiously at Cassal, who nodded. That was to be expected. Components that were common on Earth wouldn't necessarily be available here. Still, any expert worth his pay could always make the proper combinations and achieve the same results.