But that wasn’t in her nature. And, after all, Reid Malenfant was older than she was, and she knew he continued to agitate for a deeper engagement with the mystery of these Gaijin, for more probes, other missions. If he was still active, then perhaps she should be.

But, in this complicated universe, she was too damn old. The more complicated it was, the more likely it was that she would never live to see this puzzle — perhaps the greatest mystery ever to confront humanity — unraveled.

Now a technical feed faded up in Maura’s other ear. “Closing with the target at two meters per second, range just under a klick, one meter per second cross-range. Hydrazine thruster tests in progress: +X, -X, +Y, -Y, +Z, -Z, all check out. Counting down to the thruster burn to null our approach and cross-range velocities a klick above the ground. Then we’re on gyro-lock to touchdown…”

With an effort of will, Maura tuned out the irrelevant voices.

The asteroid became a wall that approached her in slow, dusty silence; the tether lines twisted before her, retaining their coils in the absence of gravity. She made out surface features, limned by sunlight: craters, scarps, ridges, valleys, striations where it looked as if the asteroid’s surface had been crumpled or stretched. Some of the craters were evidently new, relatively anyhow, with neat bowl shapes and sharp rims. Others were much older, little more than circular scars overlaid by younger basins and worn down, presumably by a billion years of micrometeorite rain.

And there were colors on Ellis’s folded-over landscape, spectral shades that emerged from the dominant gray-blackness. The sharper-edged craters and ridges seemed to be slightly bluish, while the older, low-lying areas were more subtly red. Perhaps this was some deep-space weathering effect, she thought; perhaps eons of sunlight had wrought these gentle hues.

She sighed. It really was lovely, in a quite unexpected way — like so much of the universe she found herself in. By God, I love it all, she thought. How can I retire? If I did, I would miss this.

And now, with a kiss of dust, the Bruno reached its destination.

The techs began cheering tinnily.

A year before the Bruno ’s arrival — after the AAAS meeting — Malenfant had returned to the Johnson Space Center for the first time in two decades.

The campus looked pretty much unchanged: the same blocky black-and-white buildings, with those big nursery-style numbers on their sides, scattered over square kilometers of grassy plain here at the southeast suburban edge of Houston, all contained by a mesh fence from NASA Road One — though it wasn’t called the NASA Road anymore. In the surrounding streets there were still run-down strip malls and fast-food places and 7-Elevens.

But inside the campus itself, there was no sign of the tourists who used to ride between the buildings in their long tram trains. And though there were plenty of historic-marker plaques, nobody was making history here anymore.

The cherry trees were still here, though, and the green grass still seemed to glow.

He wasn’t here to sightsee. He had come to meet Sally Brind, who ran a NASA department called the Solar System Exploration Division. He made his way to Building 31.

Inside, the air-conditioning was ferocious, a hell of a contrast to the flat, moist Houston heat outside. Malenfant welcomed the plummeting temperature; it was like old times.

Reid Malenfant had loomed over Sally Brind. He was leaning on her desk, resting his weight on big, bony knuckles. He was around twice Brind’s age, and he was a legend out of the past. And, to her, he was as intimidating as hell.

“We’ve got to get out to the solar focus,” he began.

“Hello, good morning, nice to meet you, thanks for giving up your time,” she said dryly.

He backed off a little, and stood up straight. “I’m sorry,” he said.

“Don’t tell me. At your time of life, you don’t have time to waste.”

“No, I’m just a rude asshole. Always was. Mind if I sit down?”

“Tell me about the solar focus,” she said.

He moved a pile of glossies from a chair; they were digitized artist’s impressions of a proposed, never-to-be-funded, unmanned mission to Io, Jupiter’s moon. “What I’m talking about, specifically, is a mission to the solar focus of Alpha Centauri — the nearest star system.”

“I know about Alpha Centauri.”

“Yes… The Sun’s gravitational field acts as a spherical lens, which magnifies the intensity of the light of a distant star. At the point of focus, out on the rim of the system, the gain can be hundreds of millions; at the right point, it would be possible to communicate across stellar distances with equipment no more powerful than you’d need to talk between planets. The Gaijin may be using the Centauri solar focus as a communication node. The theorists are calling it a Saddle Point. Actually there is a separate Saddle Point for each star. All roughly at the same radius, because of—”

“All right. And why do we need to go to Alpha Centauri’s focus?”

“Because Alpha was the first source of extrasolar signals. And because the Gaijin are there. We have evidence that the Gaijin entered the system at the Alpha solar focus. From there, they sent a fleet of some kind of construction or mining craft into the asteroid belt. Sally, we now have infrared signatures, showing the activity in the asteroid belt, going back ten years.”

“There is an unmanned probe en route to the asteroid belt. Maybe we should wait for its results.”

Malenfant flared. “A private initiative. Not relevant, anyhow. The solar focus — that is where the action is.”

“You don’t actually have any direct evidence of anything out at the solar focus, do you?”

“No. Only what we’ve inferred from the asteroid belt data.”

“But there’s no signature of any huge interstellar mother ship out there, at the rim. As there would have to be, if you’re right.”

“I don’t have all the answers. That’s why we have to get out there and see. And to tell the damn Gaijin we’re here.”

“I don’t see how I can help you.”

“This is NASA’s Solar System Exploration Division. Right? So, now we need to go do some exploring.”

“NASA doesn’t exist anymore,” she said. “Not as you knew it, when you were flying shuttle. The JSC is run by the Department of Agriculture—”

“Don’t patronize me, kid.”

She sighed. “I apologize. But I think you have to be realistic about this, sir. This isn’t the 1960s. I’m really just a kind of curator, of the gray literature.”

“Gray?”

“Studies and proposals that generally never made it to the light of day. The stuff is badly archived; a lot of it isn’t yet digitized, or even on fiche… Even this building is seventy years old. I bet it would be closed for good if it wasn’t for the Moon rocks.”

That was true; elsewhere in this building, 50 percent of the old Apollo samples still lay sealed in their sample boxes, still awaiting analysis, after six decades. Now that there were Japanese living on the Moon, Brind suspected the boxes would stay sealed forever, if only so they could serve as samples of the Moon as it used to be in its pristine, prehuman condition. An ironic fate for those billion-dollar nuggets.

“I know all that,” he said. “But I used to work for NASA. Where else am I supposed to go? Look — I want you to figure out how it could be done. How can we send a human to the solar focus? It will all come together, once we have a viable scheme to fix on. I can get the hardware, the funding.”

She arched an eyebrow. “Really?”

“Sure. And the science will be good. After all, we still haven’t sent a human out beyond the orbit of the Moon. We can drop probes on Jupiter, Pluto en route. We’ll get sponsorship from the Europeans and Japanese for that. The U.S. government ought to contribute, too.”