Space

At that there was a stir of interest, self-satisfied.

As his virtual light show continued to evolve, telling its own story, he glanced up at the walls around him, at the glimmer of highlights from the wood. This was a remarkable place. It was the largest structure in Edo, serving as community center and town hall and showpiece, the size of a ten-story building.

But it was actually a tree, a variety of oak. The oaks were capable of growing to two hundred meters under the Moon’s gentle gravity, but this one had been bred for width, and was full of intersecting hollowed-out chambers. The walls of this room were of smooth-polished wood, broken only subtly by technology — lights, air vents, virtual-display gear — and the ca

In contrast to the older parts of Edo — all those clunky tu

But yes, incrementally: that was the key word. Even these lunar colonists couldn’t see beyond their current projects, the next few years, their own lifetimes. They couldn’t see where this could all lead. To Malenfant, that ultimate destination was everything.

And, perhaps, Nemoto and her strange science would provide the first route map.

The little probe images had reached their destination stars.

“Here is the heart of the strategy,” he said. “A target system, we assume, is uninhabited. We can therefore program for massive and destructive exploitation of the system’s resources, without restraint, by the probe. Such resources are useless for any other purpose, and are therefore economically free to us. And so we colonize, and build.”

More probes erupted from each of the first wave of target stars, at greatly increased speeds. The probes reached new targets; and again, more probes were spawned, and fired onward. The volume covered by the probes grew rapidly; it was like watching the expansion of gas into a vacuum.

“Once started, the process is self-directing, self-financing,” he said. “It would take, we think, ten to a hundred million years for the colonization of the Galaxy to be completed in this ma

His probes were now spreading out along the Galaxy’s spiral arms, along lanes rich with stars. His Japanese audience watched politely.

But as he delivered his polished words, he thought of Nemoto and her tantalizing hints of otherness — of a mystery that might render all his scripted invective obsolete — and he faltered.

Trying to focus, feeling impatient, he closed with his cosmic-destiny speech. “This may be a watershed in the history of the cosmos. Think about it. We know how to do this. If we make the right decisions now, life may spread beyond Earth and Moon, far beyond the Solar System, a wave of green transforming the Galaxy. We must not fail…” And so on.

Well, they applauded him kindly enough. But there were few questions.

He got out, feeling foolish.

The next day Nemoto said she would take him to the surface, to see her infrared spectroscopy results at first hand.

They walked through the base to a tractor air lock and suited up once more. The infrared station was an hour’s ride from Edo.

A kilometer out from Edo itself, the tractor passed one of the largest structures Malenfant had yet seen. It was a cylinder perhaps 150 meters long, 10 wide. It looked like a half-buried nuclear submarine. The lunar surface here was scarred by huge gullies, evidently the result of strip-mining. Around the central cylinder there was a cluster of what looked like furnaces, enclosed by semitransparent domes.

“Our fusion plant,” Nemoto said. “Edo is powered by the fusion of deuterium, the hydrogen isotope, with helium-3.”

Malenfant stared out with morbid interest. Here, as in most technological arenas, the Japanese were way ahead of Americans. Twenty percent of U.S. power now came from the fusion of two hydrogen isotopes, deuterium and tritium. But hydrogen fusion processes, even with such relatively low-yield fuel, had turned out to be unstable and expensive: high-energy neutrons smashed through reactor walls, making them brittle and radioactive. The Japanese helium-3 fusion process, by contrast, produced charged protons, which could be kept away from reactor walls with magnetic fields.

However, the Earth had no natural supply of helium-3.

Nemoto waved a hand. “The Moon contains vast stores of helium-3, locked away in deposits of titanium minerals, in the top three meters of the regolith. The helium came from the Sun, borne on the solar wind; the titanium acted like a sponge, soaking up the helium particles. We plan to begin exporting the helium to Earth.”

“I know.” The export would make Edo self-sufficient.

She smiled brightly, young and confident in the future.

Out of sight of Edo, the tractor passed a cairn of piled-up maria rubble. On the top there was a sake bottle, a saucer bearing rice cakes, a porcelain figure. There were small paper flags around the figure, but the raw sunlight had faded them.

“It is a shrine,” Nemoto explained. “To Inari-samma, the Fox God.” She gri

“Shrines? At a lunar industrial complex?”

“We are an old people,” she said. “We have changed much, but we remain the same. Yamato damashi — our spirit — persists.”

At length the tractor drew up to a cluster of buildings set on the plain. This was the Nishizaki Heavy Industries infrared research station.

Nemoto checked Malenfant’s suit, then popped the hatch.

Malenfant climbed stiffly down a short ladder. As he moved, clumsily, he heard the hiss of air, the soft whirr of exoskeletal multipliers. These robot muscles helped him overcome the suit’s pressurization and the weight of his tungsten antiradiation armor.

His helmet was a big gold-tinted bubble. His backpack, like Nemoto’s, was a semitransparent thing of tubes and sloshing water, six liters full of blue algae that fed off sunlight and his own waste products, producing enough oxygen to keep him going indefinitely — in theory.

Actually Malenfant missed his old suit: his space shuttle EMU, extravehicular mobility unit, with its clunks and whirrs of fans and pumps. Maybe it was limited compared to this new technology. But he hated to wear a backpack that sloshed, for God’s sake, its mass pulling him this way and that in the low gravity. And his robot muscles — amplifying every impulse, dragging his limbs and tilting his back for him — made him feel like a puppet.

He dropped down the last meter; his small impact sent up a little spray of dust, which fell back immediately.

And here he was, walking on the Moon.

He walked away from the tractor, suit whirring and lurching. He had to go perhaps a hundred meters to get away from tractor tracks and footsteps.

He reached unmarked soil. His boots left prints as crisp as if he had stepped out of Apollo 11.

There were craters upon craters, a fractal clustering, right down to little pits he could barely have put his fingertip into, and smaller yet. But they didn’t look like craters — more like the stippling of raindrops, as if he stood in a recently plowed and harrowed field, a place where rain had pummeled the loose ground. But there had been no rain here, of course, not for four billion years.

The Sun cast brilliant, dazzling light. Otherwise the sky was empty, jet black. But he was a little surprised that he had no sense of ope