The Prefect shook his head. “Only a few hundred meters.”

“So must be robotic. A living biosphere would need—”

“They seem, from references in their clear sentences, to be ‘people’—a word they chose.”

None of this made sense to her. Sending living aliens between stars?—fantastic. She managed to get out, “Headed for Earth?”

“So we thought, at first. Forgive me, I was strictly told to reveal none of this to any but Prefects and Noughts. We believed this craft would wish to go into Earth orbit, then perhaps visit—but no.”

“Then… what…?”

“They wish to avoid Earth herself.”

“What?! But—”

“They are veering, orbiting. Coming… here.”

“But why?”

“I would like to think it is because they are devout students of the many Messages we have also detected. Perhaps they are. But from their somewhat veiled signals, their interest does indeed focus upon our Library. Perhaps they are from the origin of Messages we hold, and received a signal from independent human broadcasters.” He shrugged.

“But… then, to head to our Library—” She blinked at an idea. “Maybe they’re coming here to make contact with a Message Mind they sent out, in the far past? To learn from it what it thinks of us?”

The Prefect smiled. “A stimulating idea. Bravo!” To her surprise, he clapped his hands. Then he rushed on, speaking in a thoughtful whisper. “And so such may signal about their own ancient history. After all, our theory of cultural and technological evolution of intelligent societies holds that first comes a Listening Era, then a Message Broadcasting Period, and if possible—though doubtful! for basic physics reasons…” The Prefect paused, furrow-browed. “… an improbable Voyaging Era, of interstellar colonization.”

Rachel sat back, furiously thinking. “But… with all Earthside has to offer, a big booming biosphere—”

“Why come here, to barren Luna? To our little Library?”

“Sure, uh, why—”

“Perhaps because they do not wish to deploy into a deep grav well?—though their deceleration rates suggest they can surely bear a single mere grav and much more.”

“What do the astronomers think? Why would our very first alien visitors choose—”

The Prefect waved her words away. “Pox upon such astrophysical reasoning. They did mention liking a lesser gravity, so the Astros think they prefer Luna, but that is surely ancillary, given the rest of their clipped communications.”

“Oh.” Her thoughts scrambled to take this all in.

The Prefect smiled and spread his arms wide in a grand welcoming gesture. “Their reasoning emerged only in their signals of today, as they near our orbit. They come here because of you, our Rachel. They ask for you specifically.”

2.

Cat said, “So we’re to host disgusting alien bags of bacteria that just spew it out in all directions?”

Rachel laughed. “I forgot you’re a biosecurity officer, as your second position.”

Cat made an ironic bow. “We are the nuts that hold the bolts of this production together. I just got a protocol from Earthside on this, too. A ‘welcome’ ship has flown up, blew a bubble for these aliens. Doing the bios right now.”