"So they have," she nodded. "What we're after is an interplanetary power beam. And we've got it." She gestured to the baggage rack and a thick trunk full of papers she had put there. "That's it. The basic circuits, factors, and constants. Any competent engineer could draw up a design from them." "Hmmm ... precision work, eh?" "Obviously! It was hard enough to do on, say, Earth--you need a _really_ tight beam in just the right frequencies, a feedback signal to direct each beam at the desired outlet, relay stations--oh, yes, it was a ten-year research project before they could even think about building. An interplanetary beam has all those problems plus a number of its own. You have to get the dispersion down to a figure so low it hardly seems possible. You can't use feedback because of the time lag, so the beams have to be aimed _exactly_ right--and the planets are always moving, at miles per second. An error of one degree would throw your beam almost two million miles off in crossing one A.U. And besides being so precise, the beam has to carry a begawatt at least to be worth the trouble. The problem looked insoluble till someone in the Order of Planetary Engineers came up with an idea for a trick control circuit hooked into a special computer. My lab's been working together with the Order on it, and I was making certain final determinations for them. It's finished now ... twelve years of work and we're done." She laughed. "Except for building the stations and getting the bugs out!" * * * * * Lundgard cocked an oddly sardonic brow. "And what do you hope for from it?" he asked. "What have the psychotechs decided to do with this thing?" "Isn't it obvious?" she cried. "Power! Nuclear fuel is getting scarcer every day, and civilization is finished if we can't find another energy source. The sun is pouring out more than we'll ever need, but sheer distance dilutes it below a useful level by the time it gets to Venus. "We'll build stations on the hot side of Mercury. Orbital stations can relay. We can get the beams as far out as Mars without too much dispersion. It'll bring down the rising price of atomic energy, which is making all other prices rise, and stretch our supply of fissionables for centuries more. No more fuel worries, no more Martians freezing to death because a converter fails, no more clan feuds on Venus starting over uranium beds--" The excited flush on her cheeks was lovely to look at. Lundgard shook his head. There was a sadness in his smile. "You're a true child of the New Enlightenment," he said. "Reason will solve everything. Science will find a cure for all our ills. Give man a cheap energy source and leave him forever happy. It won't work, you know." Something like anger crossed her eyes. "What are you?" she asked. "A Humanist?" "Yes," said Lundgard quietly. Bo started. He'd known about the anti-psychotechnic movement which was growing on Earth, seen a few of its adherents, but--