Stelrae perched at her desk, puzzling over the learning tablet in front of her. She stared at the symbols shown on it: on one side, a wheel of glyphs, spinning continuously, each representing a species in the great Galactic Council. On the other side, the glyphs were arranged in a shape like a tree. The branches of the tree waved to and fro, glyphs dangling from it like a rainbow of fruits, save one: a glyph near the center that seemed to stay still. It was a humanoid figure made of lines, with a circle at the top.

Stelrae held the tablet in her claws and regarded it with deep concentration. She subconsciously turned her avian head to regard it with only one black-bead eye, weighing the question that had settled into her mind. Finally, she raised her two beaks and made a sharp squawk, drawing the attention of the older creature in the room. Prri looked up slowly from her own tablet, shifted her wings back to raise her body from its perch, and regarded Stelrae patiently. Stelrae stood as well, ruffed out her ultraviolet feathers, and began a speaking-dance of wing-flips, trills, and chirps.

“Teacher,” she said (and here she used a symbol that was equal parts “teacher,” “mother,” and “priestess”) “I understand that the first tenet of the Galactic Civilization is that every sentience is equal in worth and dignity. We strive in all things to seek a common understanding and an equal treatment of all thinking beings, and a respect and conservation of all life.”

Prri blinked and kept her gaze on her student.

“And this is reflected in the symbol of the Galactic Council,” Stelrae continued, gesturing with her learning tablet. “The symbols in the wheel turn and shift so that no species is perceived to be at the top or bottom or anywhere else, and no two species are seen as inextricably closer than any other two.”

Prri clucked her twin beaks. “The Wheel of Change, representing life itself.”

“With these principles held dear,” Stelrae said, as she twisted her neck, “I fail to understand the symbol of the Exploration Corps. Like the Galactic Council, it shows all known species, but it establishes a clear hierarchy and,” as she tapped the stick-figure symbol at the center, “It even puts humans in a central position here, with most of the other civilizations seeming to link to them. Why do we center the humans so with this symbol?”

Prri continued to regard Stelrae with one eye, as her other focused on her own tablet. She drew up an image of a human and directed it to a holographic display centered in the room. There, it pivoted lazily, its arms and legs held out to match the symbol. Prri unfurled her wings to speak more clearly.

“Tell me, fledgling, what you know of humans.”

Stelrae closed her eyes for a moment, then recited. “They are… Oxygen-breathers. Carbon-based organic chemistry frame. They came from a planet not unlike our own, with liquid water and a pleasantly-glidable atomsphere. They sustain their life processes via consuming complex chemicals and siphoning energy from the breakdown of those chemicals. The nutrients must flow in liquid form through their bodies and their chemistry is delicate, so they respond poorly to vacuum and temperatures outside a relatively narrow band. Terrible glide ratio in pleasant gases, though they move adequately through liquids. Like us, they can sense some light with their eyes, but are colorblind past violet; they can communicate with symbols made of light, fewer than we do. Unlike us, they have very complex vibration-shaping organs in the path of their gas-exchange sacs and they can vibrate the air to make sounds, so they can communicate without light-symbols too. They…”

“Hold, fledgling,” clucked Prri mirthfully. “You have demonstrated your attention to the book I wrote. You know much about what they are… Do you know who they are?”

Stelrae frowned and craned her neck. “I’ve never met one. So I believe… No.”

Prri tapped a few times on her tablet, and the hologram converted into a vast, sleek vessel. A star cruiser, drifting through the infinite black void between places. A Reacher-class vessel, one of the smallest of the crewed vessels at the Exploration Corps' command. It was the size of a small city, intended to be home to thousands of members of the Corps for dozens of years; for some, their entire lives. Reachers were the Corps' preferred tool for making first contact with previously-unmet sentient life; they glowed with coruscating light of myriad frequencies and were bedecked with hundreds of symbols and patterns, like the home of a long-nester filled with reminders of her years. These designs were intended to communicate to those who saw her, in aggregate: “This shape is intentional, and was made by minds who understand pattern, symbol, and meaning…” A first message to the soon-to-be-met sentience that other minds are coming. And among these patterns, near the front: the tree shape, with the glyph for “human” in the center.

“Did you know that there are almost no ships in the Exploration Corps that have no humans on them? We have a few: special-purpose vessels for extremophile contact, crewed only by species that can survive unique radiation or gravitational conditions, conditions we cannot yet shield a crew from. But all the rest… If a human can possibly survive on a ship, at least one of them is. Direct exposure to vacuum kills them in moments, yet they seem adamant to surround themselves with it at every opportunity. I found it curious when I was with them, and I asked one once why they didn’t just stay home. Do you know I discovered later I’d insulted her? But when she learned my intent was earnest, we traded much knowledge on the subject. She was a funny creature… Called herself…” And here, Prri eschewed the dance and did her best to force air past her tongue and beak, shaping it far more dextrously than Stelrae had ever heard one of the other teachers do… Sheh-ree

“Sherri told me stories of the early human exploreres,” Prri continued. “Before they could leave their home world, they were convinced they’d find other life in space. They had no evidence that life would exist; they kept looking for electromagnetic radiation as a clue, but all the sources they could see in those times were non-living physical phenomena.”

“They didn’t know how inefficient radio was,” Stelrae conjectured, “And how briefly a sentient culture would use it before inventing…”

“Precisely. So they set out in vast sublight ships, seeking life anyway.”

“Sublight? But the human life cycle…”

“Far too brief for sublight travel to other stars,” Prri confirmed. “They knew they were embarking on a journey they’d never finish. But their descendents grew and flourished, and eventually, after hundreds of new generations… They found the Broopala.”

A pressurized water tank on four legs filled the hologram, with a mass of plastic tentacles protruding along its perimeter. In the glass floated a massive pink jellyfish, five glowing orbs staring from the tank.

“The Broopala’s home is far from its star and encrusted in a shell of thick ice. They live in an ocean warmed by their planet’s core, the Worldsea. They’d built a vast society in the Worldsea, and never wondered if there was life beyond it… For them, pressure gradients pushed them towards the inner surface of the ice shell, and any unlucky enough to get too near that crust risked being forced by the pressure into an ice volcano, pulled into ‘the undersea,’ a realm of death and cold. It was, understandably, quite a shock to them when human explorers first entered their world from the undersea and explained the existence of a universe outside the Worldsea to them. It almost started a war.”

“What stopped them?”

“A great deal of patience and understanding from both sides. Eventually, the humans withdrew from the Worldsea. But three human generations later, the humans who lived in that star system detected a structure on the surface of the Broopala’s home. It seemed that the knowledge of existence outside the Worldsea had become too heavy for some of the Broopala to ignore. They formed the first alliance and would one day grow to become the Council.”

“So the humans are centered in the emblem because they discovered the first other Council member?”

Prri made a gesture that was equal parts dismissive and accepting, you-are-correct-given-what-you-know-but-you-do-not-yet-know-the-whole. “The Council would not be formed for many, many hundreds of years yet. And this is only one group of humans; remember, they did not yet have the ability to communicate with anything other than electromagnetic radiation. Not even all the humans were yet aware of the Broopala.

“While this was happeneing, another group of humans had found a vast desert world around another star.” The hologram shifted to show an unyielding sun beating upon an endless sea of desert; a frozen ocean of sand, motionless but for dust devils and heat mirages. “They had settled a lush planet in the same system, but made pilgrimages to this world because its chemistry suggested it had once also been a jungle of its own. But all they found was an endless sea of eroded minerals and random complex polymers. Still, they came. Some even made a permanent home there.”

“Why make a home on such a hostile world when there’s a comfortable one orbiting the same star?”

Prri paused, toying with a memory for a bit, and grinned without smiling. “Humans have a love of puzzles bordering on hatred. Their science told them life had been here, yet they found none. Sometimes they take to a contradiction like a first-time nest-builder takes to a sturdy limb.

“In any event, they were proven right.” And out of the ocean of sand grew irridescent cities of plastic and stone. “Though time and weather had ground it to pieces, the sand proved to be the remnants of cities made of living shape alloys. Their builders had long since died, but the cities knew the shapes they were made to take, and when exposed to the right catalysts and radiation, they took them again. And they also knew their secrets; they were shelter and library for the ones who had made them. The cities called themselves ‘Shhrishh,’ and you see them here…” Prri gestured to Stelrae’s tablet and one of the glyphs near the center of the Exploration Corps' symbol glowed briefly.

“The living computers in each Exploration Corps' ship.”

“Good,” replied Prri. “Shhrishh also told these humans of a nearby star their people had visited, with its own life. The humans set out to find it, and in a few generations, they met Ygg.” The hologram showed a world fully covered by a dense forest, leaf canopy over every square meter of land and vines as thick as tree trunks stretching across oceans.

“Ygg, the World Tree, a mind… Made of all the plants of its world and the connections between them.” Stelrae tapped a multi-branching glyph in the Exploration Corps' symbol, which sat beside the human and Shhrishh glyphs.

“Your attention to your studies honors us all,” Prri recited. “Ygg was very willing to teach the humans many things, in exchange for stories of them and their travels. It was Ygg who taught them of the ways to communicate through media other than the electromagnetic, and how to move themselves through those media as well. They quickly reconnected with all their scattered species throughout the cosmos, and a grand era of exploration began.” Here, the hologram showed dozens of human vessels, flowing out through the galaxy. As a panoply of meetings played out, markings appeared on the bows of the human ships, each ship sporting a different pattern.

“Those markings… They are similar to the glyphs used by the Council. Why are they different on each ship?”

“The humans would put them there. Each ship, upon meeting someone new, their captain would ask those they met for a symbol and add it to their hull. Sherri explained to me this was a combination of two ancient customs: a ‘passport,’ which was a symbol humans used when they thought of their world as many separate places and you would get a mark to show you had been permitted to be a guest in one. And a repurposing of the ‘victory mark,’ which was a symbol from a more brutal time for them when they built their ships to kill each other and they would make a mark for each such vessel they had destroyed. It symbolized glory to them, and in some way, it still did.”

Stelrae tilted her head in puzzlement. “Glory?”

“As I said, humans have a complicated relationship with puzzles, and they sometimes see life itself as a grand puzzle. Possibly the grandest of all. Did you know that most members of the Council didn’t believe there was any life in the home system of the Zrrzans? It was the humans who insisted the bands of rapidly-changing magnetic flux between the moons of the system’s largest gas giant had the wrong pattern to be purely explained by planetary physics. One of them defied the will of the Council by creating a massive fission reaction based on one of their ancient weapons to disrupt that flux… And he would have lost his privileges as a captain if the flux hadn’t answered back. Although apologies were in order because the answer was soon translated as ‘That was very loud, never do that again.’ Even the most recently-recognized sentience the Council is aware of is mostly the humans' doing. They were convinced they’d discovered a species of extremely-low-metabolism life in the calcium deposits of a volcanic world. They spent eight generations crafting and transmitting the message ‘Hello,’ and another three waiting for the response. It was only recently that they decoded a pattern of earthquakes on the planet that could be interpreted as ‘Hi,’ and so the Corps petitioned the council to admit them under the provisional name ‘Calcans’. Some of us still aren’t sure they’re sentient,” Prri muttered.

Stelrae idly turned the tree of symbols around on her tablet, trying to find an angle to view them all at once. “So the Council gifted the Exploration Corps a symbol reflecting the way the humans had brought the Galactic Civilization together…”

The dismiss-accept gesture again. “The Council had deep misgivings about this symbol and still does, even now. It was the Corps itself that chose its own symbol. For before the Galactic Council was formed, others had adopted the tradition the humans shared with them and had adorned their own explorers with such symbols. The symbol of the Corps is a collective overlay.”

At the push of a button on Prri’s tablet, the tree-symbol exploded into dozens upon dozens of individual clusters: Human and Broopala, Human and Shhrishh, Human and Ygg, Shhrishh and Galvani, Human and Galvani and Vordok, Human and Felwraith, Shhrishh and Felwraith and Arachronae… Stelrae even saw Human, Shhrishh, Galvani, Vordok, and a symbol she wore as a pendant around her neck: Erynnes. Then Human, Shhrishh, Erynnes, Zrrrzans, and… She surmised Calcans, though she would have to confirm her suspicions later… Prri tapped a second button, and the clusters drew back together, the same symbols merging, lines forming to show the original clusters.

“The Galactic Council is a place where every sentience has equal worth and dignity,” said Prri. “We seek mutual understanding, support, compassion, protection, and familiarity. But it was the humble—but persistent—request of the whole of Exploration Corps, not only the humans, that the symbol they bear highlight the perils of those first connections, the way they burn bright against the void between us, and how life itself grows in so many places, thriving in the dark, quietly waiting for someone to reach out and contact it. And how vital to Life itself that first contact is.” Prri paused for a moment. “And, yes, though we are all equal in the Galactic Civilization, the humans do take pride in how many of those lines were drawn by them.”

Stelrae closed her eyes and was silent for several moments. “Teacher,” she finally said with some hesitation, “Is it impertinent of me to ask why you left the Corps? I do not wish to question your decision, only… When you speak of them, you seem quite happy.”

The older Erynnes crossed the room and stood stoically in front of the younger, considering how the hues on her pupil’s smaller wing feathers matched her own… “That is an impertinent question to ask a teacher, but I will answer as a mother. We do not… Reproduce well on ships or other worlds. I was happy out there… But I am happy here too. I could not join the Nesters out there, could not bring my own eggs to the Hatchery nor sit on the eggs of our people. Ah, to be able to do both! But there is something of our trees that we need, and no way has been found to make the great trees thrive in the void, no matter how great the ship.” She put a comforting wing around the child. “I couldn’t be both an Explorer and one of your Mothers, fledgling. But when you have grown? Perhaps I shall return, if I am not too old. You could even join me.”

Stelrae fluffed up at the unusual, but not unwelcome, contact. She considered life on one of the great Reachers, living alongside so many other creatures so unlike herself, learning from them… But then she thought of the cold, the suffocating vacuum outside. She imagined beating her wings uselessly against nothing, floating without control, drifting forever… She shuddered. Prri removed her wing.

“Now, you haven’t actually answered my question yet,” danced Prri in a playfully-formal pose. “Do you know who humans are?”

Stelrae closed her eyes and paused again, the setting sun catching her plumage to enflame her silhouette as though thought itself radiated from her, like the black-body radiation of a Shhrishh cogitation-tower at full blast. “They are… Explorers. Though not sturdy against the void, nor long of life to journey vast distances between worlds, they left their home anyway, seeking new life, compelled by… No. In truth, I cannot answer who they are. What compels them? Their home must be so much more comfortable to them than any other place they have found… What drove them to leave it in the first place?”

Prri looked out to the balcony, and beyond it, to the setting sun. The slanting light gave way to individual points of nighttime illumination on countless kilometers of sturdy trees, out to the horizon. Each tree home to dozens to hundreds of her people, living their lives at ease, bathed in the warm light. Tens of thousands in the places she could see, and beyond that, billions more, nesting, flying, learning, growing, living, dying… And so many who would do so, every day of their lives, under that sun and that sun alone.

Perhaps even if I am too old…

“Unlike us,” Prri danced slowly, “Humans can reproduce in the void. Sherri and her mate lived on our ship together, and they did so twice while we were crewmates.” She again blew air past her tongue and beaks. Jhhhhheffff. “Jeff was her mate. I saw their nestlings often, and grew quite fond of them.” Prri stopped. Stelrae stared at her patiently.

“There are two things you should know about humans, things they do when they are very young. The first is something they do very soon after they are born. They hatch before full development, and they use the first few weeks of life to organize their senses and brains into a sentient mind. From the moment a human’s sensorium can perceive things outside themselves… They reach for them.

“The second is that they will imagine sentience in things that have none. Complex machines, constructs, inanimate objects, vegetation… I once watched Sherri’s oldest nestling hold an entire conversation with an automatic door. Both sides of the conversation. It’s as if something in them demands the universe around them be alive. They will accept nothing less.”

In the rapidly-darkening sky, ten thousand points of light twinkled into view. They hung motionless, as they had, and would, for hundreds of thousands of nights. One point among them moved silently. It drifted from the horizon, curved up and up, flashed twice, and vanished.