She nodded. “Other worlds, other minds, strange—but they have suffered the same past.”
“True. This is not a matter of dry certainties. It is a quest for archeological wisdom.”
She whirled, her mouth a grimace, eyes wild. “Whatever they’re afraid of it could be, be—comin’ right atchya!”
He was calm, further confusing her. He gave her a cautious, precise, throat clearing. “I have an allergy to dogma, including my own.”
“What’s your dogma?”
“Placing the Library on Luna, safely away from the torrents of Earth, was a primary motive. Best to contemplate the stars where one can see them anytime. In other words, take the long view.”
She was getting more frustrated by his blithe manner, but resisted raising her voice. “Look, you wanted me to go back to studying decrypting SETI messages, but this, this—I just couldn’t give it up.”
“Research is not devised, it is distilled.”
She let out a loud, barking laugh. “Building logic towers from premises wrung out of thin air, more like it.” “You have got it nearly right.”
“Nearly?”
He eyed her narrowly. “We think of the Elizabethan world as one we perceive through our own reductive devising. We think of it as populated by the Queen and Ben Jonson and the Dark Lady and the Bard and a raucous theatre full of groundlings. That’s what we know, from some texts. But the real Elizabethan world had a lot more people in it than that, and countless more possibilities. Here at the Library, we deal with not a mere handful of centuries. We have received messages sent across thousands of light years, from beacons erected by societies long dead.”
“Well, yes—”
“So we need to know more, before deciding anything.”
She finally let her anger out. “Nonsense! This is a threat! People need to know.” She spread her hands, beseeching him.
“Go and think some more. You are following the right path.”
With a wave he dismissed her.
Catkejen came in from a date, all fancied out in a maroon, bioweb Norfolk jacket with fluorescent yellow spirals down the arms, and found Rachel calculating some ideas. “Actual penciling out! Pushing graphite! You should get outside sometime, y’know.”
Feeling every inch a pedant, Rachel rose, stretched. “I was backtracking those red stars that had hunkered down.”
“You mean the ones that prob’ly knocked out our probes?”
“Yes, plus ones we’ve seen from the 550 A.U. telescopes, that had ruins on them.”
“So you’re running backward their orbits around the galaxy?” A disbelieving frown.
“Yes, it’s a tough many-body problem—”
“Hey, another example of cross-field confusion. We already have that!”
This was how Rachel learned that astronomers had developed a reverse-history code of extraordinary ability. They had first evolved it to study galactic stellar evolution of spiral arms. Which led to her next audience with the Prefect.
She walked—no, she decided, she skipped with schoolgirl joy in the low grav— out of the advanced computational dome, feeling as if she had returned from a great distance.
She blew past the Prefect’s office staff and marched straight in on the great man, who was staring at a screen. He looked up, not showing any surprise. “You have more.” Not a question.
She flipped on her personal Artilect interface so it projected an image on the office 3D display. “This shows the dwarf stars our probes and the 550 A.U. ‘scopes found to be defensive or destroyed. No particular correlation between their locations, notice.”
He merely nodded. She had tagged the forty-three cases in bright green. They were scattered through a volume more than a thousand light years on a side—still a mere bubble in the colossal galactic disk. “Now let’s run the galaxy backward.”
The green dots arced through their long ellipses. The slow spin of the galaxy itself emerged as the bee swarms of stars glided in stately measure. The Sun took a quarter of a billion years to cycle in its slow orbit at about two hundred kilometers a second, taking more than a thousand years to move a light year. Humanity’s duration was less than a thousandth of one galactic cycle. From SETI messages marking funeral pyre societies, the Librarians knew that humans were mayflies among sentient cultures, the newest kids on the block.
The Prefect watched the backward-running swarm and raised his eyebrows as the green dots slowly drew nearer each other. “They follow s omewhat different orbits, bobbing up and down in the galactic plane, brushing by nearby stars, suffering small tilts in their courses,” she said, as though this wasn’t obvious. Was she making too much of this? She told herself a sharp no and went on.
“I can see some, well, clumps of several green specks forming,” the Prefect said. “They seem to be …” surprise pitched his voice into a tenor note “… occasionally passing within a few light years of each other. There! And now …” a pause as four dots swooped together “… another cluster.”
Rachel made herself use her flat, factual voice. “Stats show these were nonrandom, four sigmas out from any bell curve odds.”
“They … group … at different times. How far into the past are we now?”
“Six million years.”
He frowned, pursed his lips. “I have never seen this before.”
“Astronomers study star dynamics. This is about the hunkered-down planets, or the ones destroyed, orbiting those stars.”
The Prefect gave her a sour smile. “So this is another example of the perils of specialization.”
“Um, yessir.” Let the idea percolate … The Prefect bit. “Which means?”
“The endangered worlds were near each other, millions of years ago. Whatever attacked them—killing some societies entirely, scaring others so much they still remember it, guard against it—came at them when they were close to each other.”
She paused. Let him figure it out. . .
“Whatever menace does this …” The Prefect let his puzzled sentence trail off.
“Wormholes lie somewhere in those intersecting orbits.”
The Prefect stiffened. “We know of no wormholes!”
“Right. Absence of evidence is not evidence of absence, as
