But finally he thought of something he could say that didn't make him feel worse, and he thought maybe it had even made her feel better, a little. He said, "I love you." It seemed like it worked, he said, and so he said it again and again.

And that is all I remember about him except for when we set down and he left the ship. Only I want to say this. I know he was crazy, and if you read this and want to tell me I was crazy too to hang out with him in the break area like I did for so long, that's all right. I knew he was crazy, but he was somebody new and it was kind of fun to pull it out of him like I did and see what he would say.

Besides, he was a lot older than I am and his face had all these lines because of being down there so long and practically starving, so he was fun to look at, and the other thing was the color. The ship is all white, the walls and ceilings and floor and everything else. That makes it easy to spot fluid leaks and sometimes shorts that start little fires someplace. But all that white and the white uniforms and so on seem like they just suck the color out of everything except blood.

Only it never sucked the color out of him, and that made him special to me. Nice to look at, and fun, too. I remember seeing him walking along Corridor A the last time. He was headed for the lock and going out, and I knew it from the old, old dress blues and the little bag in his hand. And I thought, oh shit, that's the last color we had and now he's going and this really licks.

And it did, too.

So I ran and said goodbye and how much I was going to miss him and called him Mate and all that.

You know. And he was nice and we talked a little bit more, just standing there in Corridor A.

Of course I put my elbow in it, the way I always did sooner or later. I said about the woman that had been dirtside with him, was she still alive when we took him off, because he'd said how sick she was, and I thought he wouldn't go off and leave her.

He sort of smiled. I never had seen a smile like that before, and I don't ever want to see another one.

"She was and she wasn't," he said. "There were things inside her, eating the corpse. Does that count?"

I said no, of course not, for it to count they would have to have been part of her.

"They were," he said, and that was the real end of it.

Only he turned to go, and I wanted to walk with him at least 'til he got to the lock. Which I did. And talking to himself I heard him say, "She had been so beautiful. Just so damned beautiful."

All right, his mind had blown, like everybody says. But sometimes I can almost see him again when I'm in my bunk and just about asleep. He smiles, and there's somebody standing behind him, but I can't quite see her.

Not ever.

The Hydrogen Wall

GREGORY BENFORD.

Gregory Benford [www.authorcafe.com/benford] is a plasma physicist and astrophysicist, and one of the leading SF writers of the last twenty-five years. He is a science columnist for Fantasy & Science Fiction, and in 1999 published his first popular science book, Deep Time. One of the chief spokesmen of hard SF of the last three decades, Benford is articulate and contentious, and he has produced some of the best fiction of recent decades about scientists working (including some unpleasant realism) and about the riveting and astonishing concepts of cosmology and the nature of the universe. Among his many awards is the 1990 United Nations Medal in Literature. His most famous novel is Timescape (1980), his most recent, Beyond Infinity (2004). Many of his (typically hard) SF stories are collected in In Alien Flesh (1986) and Matters End (1995).

"The Hydrogen Wall" was published in Asimov's, which had another strong year, although some of its thunder (and its best writers) have occasionally been lured away to the high-paying electronic competition. It often seems to amuse Benford to portray something politically offensive, perhaps to evoke outrage and argument, or perhaps to weed out those who aren't there for the hard SF. Whatever the purpose, it is certainly the case in this story.

-for Fred Lerner Hidden wisdom and hidden treasure-of what use is either?

-Ecclesiasticus 20:30 "Your ambition?" The Prefect raised an eyebrow.

She had not expected such a question. "To, uh, translate. To learn." It sounded lame to her ears, and his disdainful scowl showed that he had expected some such rattled response. Very well then, be more assertive. "Particularly, if I may, from the Sagittarius Architecture."

This took the Prefect's angular face by surprise, though he quickly covered by pursing his leathery mouth. "That is an ancient problem. Surely you do not expect that a Trainee could make headway in such a classically difficult challenge."

"I might," she shot back crisply. "Precisely because it's so well documented."

"Centuries of well-marshalled inquiry have told us very little of the Sagittarius Architecture. It is a specimen from the highest order of Sentient Information, and will not reward mere poking around."

"Still, I'd like a crack at it."

"A neophyte-"

"May bring a fresh perspective."

They both knew that by tradition at the Library, incoming candidate Librarians could pick their first topic. Most deferred to the reigning conventional wisdom and took up a small Message, something from a Type I Civilization just coming onto the galactic stage. Something resembling what Earth had sent out in its first efforts. To tackle a really big problem was foolhardy.

But some smug note in the Prefect's arrogant gaze had kindled an old desire in her.

He sniffed. "To merely review previous thinking would take a great deal of time."

She leaned forward in her chair. "I have studied the Sagittarius for years. It became something of a preoccupation of mine."

"Ummm." She had little experience with people like this. The Prefect was strangely austere in his unreadable face, the even tones of his neutral sentences. Deciphering him seemed to require the same sort of skills she had fashioned through years of training. But at the moment she felt only a yawning sense of her inexperience, amplified by the stretching silence in this office. The Prefect could be right, after all.She started to phrase a gracious way to back down.

The Prefect made a small sound, something like a sigh. "Very well. Report weekly."

She blinked. "Um, many thanks."

Ruth Angle smoothed her ornate, severely traditional Trainee shift as she left the Prefect's office, an old calming gesture she could not train away. Now her big mouth had gotten her into a fix, and she could see no way out. Not short of going back in there and asking for his guidance, to find a simpler Message, something she could manage.

To hell with that. The soaring, fluted alabaster columns of the Library Centrex reminded her of the majesty of this entire enterprise, stiffening her resolve.

There were few other traditional sites, here at the edge of the Fourth Millennium, that could approach the grandeur of the Library. Since the first detection of signals from other galactic civilizations nearly a thousand years before, no greater task had confronted humanity than the learning of such vast lore.

The Library itself had come to resemble its holdings: huge, aged, mysterious in its shadowy depths. In the formal grand pantheon devoted to full-color, moving statues of legendary Interlocutors, giving onto the Seminar Plaza, stood the revered block of black basalt: the Rosetta Stone, symbol of all they worked toward. Its chiseled face was nearly three millennia old, and, she thought as she passed it, endearingly easy to understand. It was a simple linear, one-to-one mapping of three human languages, found by accident. Having the same text in Greek II, which the discoverers could read, meant that the hieroglyphic pictures and cursive Demotic forms could be deduced. This battered black slab, found by troops clearing ground to build a fort, had linked civilizations separated by millennia.

She reached out a trembling palm to caress its chilly hard sleekness. The touch brought a thrill. They who served here were part of a grand, age-old tradition, one that went to the heart of the very meaning of being human.

Only the lightness of her ringing steps buoyed her against the grave atmosphere of the tall, shadowy vaults. Scribes passed silently among the palisades, their violet robes swishing after them. She was noisy and new, and she knew it.

She had come down from low lunar orbit the day before, riding on the rotating funicular, happy to rediscover Luna's ample domes and obliging gravity. Her earliest training had been here, and then the mandatory two years on Earth. The Councilors liked to keep a firm hold on who ran the Library, so the final scholastic work had to be in bustling, focal point Australia, beside foaming waves and tawny beaches. Luna was a more solemn place, unchanging.

She savored the stark ivory slopes of craters in the distance as she walked in the springy gait of one still adjusting to the gravity.

Sagittarius, here I come.

Her next and most important appointment was with the Head Nought. She went through the usual protocols, calling upon lesser lights, before being ushered into the presence of Siloh, a smooth-skinned Nought who apparently had not learned to smile. Or maybe that went with the cellular territory; Noughts had intricate adjustments to offset their deeply sexless natures.

"I do hope you can find a congruence with the Sagittarius Architecture," Siloh said in a flat tone that ended each sentence with a purr. "Though I regret your lost effort."

"Lost?"

"You will fail, of course."

"Perhaps a fresh approach-"

"So have said many hundreds of candidate scholars. I remind you of our latest injunction from the Councilors-the heliosphere threat."

"I thought there was little anyone could do."

"So it seems." Siloh scowled. "But we cannot stop from striving."

"Of course not," she said in what she hoped was a demure manner. She was aware of how little she could make of this person, who gave off nothing but sentences. Noughts had proven their many uses centuries before. Their lack of sexual appetites and apparatus, both physical and mental, gave them a rigorous objectivity. As diplomats, Contractual Savants, and neutral judges, they excelled. They had replaced much of the massive legal apparatus that had come to burden society in earlier centuries.

The Library could scarcely function without their insights. Alien texts did not carry unthinking auras of sexuality, as did human works. Or more precisely, the Messages might carry alien sexualities aplenty, however much their original creators had struggled to make them objective and transparent. Cutting through that was a difficult task for ordinary people, such as herself. The early decades of the Library had struggled with the issue, and the Noughts had solved it.

Translating the Messages from a human male or female perspective profoundly distorted their meaning. In the early days, this had beclouded many translations. Much further effort had gone to cleansing these earlier texts. Nowadays, no work issued from the Library without a careful Nought vetting, to erase unconscious readings.

Siloh said gravely, "The heliosphere incursion has baffled our finest minds. I wish to approach it along a different path. For once, the Library may be of immediate use."

Ruth found this puzzling. She had been schooled in the loftier aspects of the Library's mission, its standing outside the tides of the times. Anyone who focused upon Messages that had been designed for eternity had to keep a mental distance from the events of the day. "I do not quite..."

"Think of the Library as the uninitiated do. They seldom grasp the higher functions we must perform, and instead see mere passing opportunity. That is why we are bombarded with requests to view the Vaults as a source for inventions, tricks, novelties."

"And reject them, as we should." She hoped she did not sound too pious.

But Siloh nodded approvingly. "Indeed. My thinking is that an ancient society such as the Sagittarius Architecture might have encountered such problems before. It would know better than any of our astro-engineers how to deal with the vast forces at work."

"I see." And why didn't I think of it? Too steeped in this culture of hushed reverence for the sheer magnitude of the Library's task? "Uh, it is difficult for me to envision how-"

"Your task is not to imagine but to perceive," Siloh said severely.

She found Noughts disconcerting, and Siloh more so. Most chose to have no hair, but Siloh sported a rim of kinked coils, glinting like brass, as if a halo had descended onto his skull. His pale eyelashes flicked seldom, gravely. Descending, his eyelids looked pink and rubbery. The nearly invisible blond eyebrows arched perpetually, so his every word seemed layered with artifice, tones sliding among syllables with resonant grace. His face shifted from one nuanced expression to another, a pliable medium in ceaseless movement, like the surface of a restless pond rippled by unfelt winds. She felt as though she should be taking notes about his every utterance. Without blinking, she shifted to recording mode, letting her spine-based memory log everything that came in through eyes and ears. Just in case.

"I have not kept up, I fear," she said; it was always a good idea to appear humble. "The incursion-"

"Has nearly reached Jupiter's orbit," Siloh said. The wall behind the Nought lit with a display showing the sun, gamely plowing through a gale of interstellar gas.

Only recently had humanity learned that it had arisen in a benign time. An ancient supernova had once blown a bubble in the interstellar gas, and Earth had been cruising through that extreme vacuum while the mammals evolved from tree shrews to big-brained world-conquerors. Not that the sun was special in any other way. In its gyre about the galaxy's hub, it moved only fifty light years in the span of a million years, oscillating in and out of the galaxy's plane every thirty-three million years-and that was enough to bring it now out of the Local Bubble's protection. The full density of interstellar hydrogen now beat against the Sun's own plasma wind, pushing inward, hammering into the realm of the fragile planets.

"The hydrogen wall began to bombard the Ganymede Colony yesterday," Siloh said with the odd impartiality Ruth still found unnerving, as though not being male or female gave it a detached view, above the human fray. "We at the Library are instructed to do all we can to find knowledge bearing upon our common catastrophe."

The wall screen picked up this hint and displayed Jupiter's crescent against the hard stars. Ruthwatched as a fresh flare coiled back from the ruby, roiling shock wave that embraced Jupiter. The bow curve rippled with colossal turbulence, vortices bigger than lesser worlds. "Surely we can't change the interstellar weather."

"We must try. The older Galactics may know of a world that survived such an onslaught."

The sun's realm, the heliosphere, had met the dense clump of gas and plasma eighty-eight years before. Normally the solar wind particles blown out from the sun kept the interstellar medium at bay. For many past millennia, these pressures had struggled against each other in a filmy barrier a hundred Astronomical Units beyond the cozy inner solar system. Now the barrier had been pressed back in, where the outer planets orbited.

The wall's view expanded to show what remained of the comfy realm dominated by the Sun's pressure. It looked like an ocean-going vessel, seen from above: bow waves generated at the prow rolled back, forming the characteristic parabolic curve.

Under the steadily rising pressure of the thickening interstellar gas and dust, that pressure front eroded. The sun's course slammed it against the dense hydrogen wall at sixteen kilometers per second and its puny wind was pressed back into the realm of solar civilization. Pluto's Cryo Base had been abandoned decades before, and Saturn only recently. The incoming hail of high energy particles and fitful storms had killed many. The Europa Ocean's strange life was safe beneath its ten kilometers of ice, but that was small consolation.

"But what can we do on our scale?" she insisted.

"What we can."

"The magnetic turbulence alone, at the bow shock, holds a larger energy store than all our civilization."

Siloh gave her a look that reminded her of how she had, as a girl, watched an insect mating dance.

Distant distaste. "We do not question here. We listen."

"Yes, Self." This formal title, said to be preferred by Noughts to either Sir or Madam, seemed to please Siloh. It went through the rest of their interview with a small smile, and she could almost feel a personality beneath its chilly remove. Almost.

She left the Executat Dome with relief. The Library sprawled across the Locutus Plain, lit by Earth's stunning crescent near a jagged white horizon. Beneath that preserved plain lay the cryofiles of all transmissions received from the Galactic Complex, the host of innumerable societies that had flourished long before humanity was born. A giant, largely impenetrable resource. The grandest possible intellectual scrap heap.

Libraries were monuments not so much to the Past, but to Permanence itself. Ruth shivered with anticipation. She had passed through her first interviews!-and was now free to explore the myriad avenues of the galactic past. The Sagittarius was famous for its density of information, many layered and intense. A wilderness, beckoning.

Still, she had to deal with the intricacies of the Library, too. These now seemed as steeped in arcane byways and bureaucratic labyrinths as were the Library's vast contents. Ruth cautioned herself to be careful, and most especially, to not let her impish side show. She bowed her head as she passed an aged Nought, for practice.

The greatest ancient library had been at Alexandria, in Afrik. An historian had described the lot of librarians there with envy: They had a carefree life: free meals, high salaries, no taxes to pay, very pleasant surroundings, good lodgings, and servants. There was plenty of opportunity for quarreling with each other.

So not much had changed....

Her apartment mate was a welcome antidote to the Nought. Small, bouncy, Catkejen was not the usual image of a librarian candidate. She lounged around in a revealing sarong, sipping a stimulant that was scarcely allowed in the Trainee Manual.

"Give 'em respect," she said off-hand, "but don't buy into all their solemn dignity-of-our-station stuff.

You'll choke on it after a while." Ruth grinned. "And get slapped down."

"I kinda think the Librarians like some back talk. Keeps 'em in fighting trim."

"Where are you from?-Marside?"

"They're too mild for me. No, I'm a Ganny."

"Frontier stock, eh?" Ruth sprawled a little herself, a welcome relief from the ramrod-spine posture the Librarians kept. No one hunched over their work here in the classic scholar's pose. They kept upright, using the surround enviros. "Buried in ice all your life?"

"Don't you buy that." Catkejen waved a dismissive hand, extruding three tool-fingers to amplify the effect. "We get out to prospect the outer moons a lot."

"So you're wealthy? Hiding behind magneto shields doesn't seem worth it."

"More cliches. Not every Ganny strikes it rich."

The proton sleet at Ganymede was lethal, but the radiation-cured elements of the inner Jovian region had made many a fortune, too. "So you're from the poor folks who had to send their brightest daughter off?"