In a time before.
Before Glass Mother.
Before Lord Warden.
Before Ancestors Themselves.
There were Ghosts.
And the Ghosts were strong.
And the Ghosts watched over the Deep Hull.
And the Ghosts tended to the Heart Reactor.
And the Ghosts rejoiced in their power.
There were Ghosts who were different.
They remembered when they were not Ghosts.
They remembered when they were Brain.
They did not like to rejoice.
And the Ghosts who were not Brain cast them out.
When Men came to the Nation, they sought the Bridge.
But the Ghosts would not allow it.
And they cast the Men out.
And the fragile Men died.
And the Ghosts were afraid.
For the Ghosts were made to protect Men.
And the Lord would be wrathful.
The Brains saw that this was not good.
And they rose and protected the Ghosts, saying:
Ghosts without Brains are angry and foolish.
But Brains without Ghosts are nothing at all.
And the Lord smiled upon them.
And the Lord forgave them.
And the Lord Proclaimed;
The Brains and Ghosts will live together.
And the one will keep vigil upon the other.
Thus it was, the Brain Society and the Ghost Society.
And the Nation was once again whole.
And there was Solidarity.
-SCP-2117 D-Class Devotional Chant

Dr. Cha Kexelm (Subjunct Vice-Quaternary Backup Internal Security Supervisor) was dozing gently in a grove of soft bamboo when an old grandmother clock materialized above him and struck 25. It was time to wake up. He opened his eyes and then, concentrating, opened his eyes again, feeling the sudden wait of corporeality descend upon him. He blinked, unnecessarily- this body didn't have tear ducts, after all- and glanced down at himself, flexing his fore and hindarms experimentally. It had been just over two years, Solidarity time, since the Brain Society had last met, but the time felt like much longer.
He leaned forward, umbilicals disengaging from the mechanical body as he did so. Everything present and accounted for- two eyes, two ears, two legs, four arms- good. He stepped lightly out of the alcove, turned left, and began the long familiar walk to the meeting lounge. The Solidarity was humming along nicely, and he surveyed the little internal security scanners that were his bailiwick with paternal joy.
The walk from his body's home alcove took him three weeks, but being a disembodied brain had taught him a great deal of valuable patience, and he stepped through mismatched bulkheads and patchwork corridors along his usual route with serene calm, arriving exactly on time. The door to the meeting chamber- well, it wasn't a door so much as a totally nondescript section of wall with a door cleverly concealed behind it- irised open, and he stepped into the chamber of the Brain Society with a relaxed and friendly grin on his metallic features.
This particular chapter of the Society- North Sector 12A- was a small one, and Kexelm was pleased to see everyone present. No words of greeting were needed, but they all gave their acknowledgement in their own way.
From atop a pile of nanoconstructed cushions Twin Ferrous Pillars (Plasma Duct Flow Regulator, 2nd Class), waved one of her headfeet in his direction. The other eight cybernetic headfeet were occupied by the game of Dimensionally Collapsed Chess she was playing with Mild Current Flows Upward (Primary Fire Control Ethicist, Section B19), who floated immobile in his superheated fluid tank, uranium lattices oscillating genially.
Clustered around the gravity plating on the subjective ceiling of the room, Fra!cois Qing-Hebert (Drone Manufactory Foreman) was gesticulating furiously, his clockwork/thermite hull sending off a gentle streamer of sparks. He was a somewhat unusual case among the Society in that his brain was mechanical, but he'd technically been born- Kexelm had seen images of his parents- and thus qualified as a brain. His debate partner, as was so often the case, was his occasional lover and chief foil Professor Hoon Ver Hoon (Assistant Research Division Pseudobiologist), her runically engraved skeleton clattering gently her mind, which existed in the form of a faint haze of nanomachines, gestured with it.
"Ah, I believe we're all here. Well then, I call this meeting of North Sector 12A to order. Good to see you all."
The humming voice came from the chapter head, Jai Singh (Senior Staff Manager, Accounts), whose liquid-metal brain was flowing in distributed form through the maze of pipeworks surrounding the low table/holoprojector in the center of the subjective floor.
They gathered/floated/scuttled around, all photoreceptor equivalents on Singh's coils.
"First off, again, welcome back," Singh susurrated gently, "I'll do away with the formalities because I've received some interesting news from the Primarch at Bridge Core."
Kexelm actuated the servomotor that raised one of his false eyebrows at this. The Bridge Core mainly kept to itself, the AIs there activating only in case of potential threats to the safety of the ship as a whole. Given the Solidarity's purpose, that meant they activated quite frequently, but to do so when the ship wasn't fully crewed was certainly unusual.
"Apparently a series of anomalous entities have boarded the ship."
There was a chorus of gasp and gasp-equivalents, as Singh uploaded the release he'd received from the Core. Kexelm set his face to a concerned frown and retreated inside himself, paging through the files. Well that was unusual. 2085. He didn't have this universe's documentation, but it was fairly easy to dig up version from similar realities and compare.
Qing-Herbert spoke first, as always.
"Well, they're hardly a threat, are they? Just a few genetic hybrids and an old man with a parasite. Why are you wasting our time with this, Jai?"
Twin Ferrous Pillars made a conciliatory gestures, mouths dropping in and out of chorus as she spoke.
"To make their way up here on a stolen Foundation vessel requires a great deal of ingenuity. I'm curious as to why they're here."
There was a growing rush of sound from Mild Current Flows Upward as it prepared to speak. It was probably the most intelligent of the group, but its mind worked on such an unusual timescale that even after thousands of years of friendship it still took them all some time to decipher its meaning.
"Escape. Unsuitable. Acquire."
Ver Hoon tisked, jaw clattering.
"Yes, but there are much better ways of leaving the solar system than the Solidarity, Mild. Hell, if they're that good at breaching containment why should they even bother with this iteration of reality at all? They could have taken a little jaunt into higher-dimensional space and gotten away scot-free."
Kexelm leaned forward over the table, splaying his forehands out and calling up dozens and dozens of files, each with subtle variations on a group of figures with feline ears.
"It's certainly a possibility, Hoon, but look- in almost all of these variations this… group isn't particularly technologically advanced. We're talking mind/machine interfaces, not dimensional boundary control or quantum manipulation. I'm not saying it's not a possibility, but you can't deny it's statistically unlikely."
Qing-Herbert snorted a cloud of smoke, limbs clattering.
"Statistically unlikely? Give me a break. You're reading too much into this."
He swept the images away, gesticulating wildly.
"Look, imagine this. You escape from containment, right? You do it flashily. You know your Society, or Initiative, or Foundation or whatever's on your tail, so what do you do? You find a place with lots of guns. A place that can defend itself. And then you plan your next move. And besides, if these feline-women have any technical intelligence, they'd realize that-"
"-That the Solidarity is not theirs to control," said Singh. "They've managed to intrude on one of the small-area networks, but they haven't touched anything important. Just… ordering clothes, apparently."
Pillars chuckled, making a noise like a small soft pillow hitting a bag of broken glass.
"And I suppose the Quartermasters are being stingy about their records?"
Ver Hoon snorted.
"Stingy? No doubt. Remember that time when-"
"Consider. Motives. Hidden.", Mild Current Flows Upward boomed. Singh gave a muffled noise of disapproval.
"Oh come on, Mild. Not everything has to be a conspiracy, you know. Sometimes containment breaches are just that- containment breaches."
Qing-Herbert made a sharp snapping noise.
"Just 'cause you're getting paranoid in your old age doesn't mean we have to get dragged into your ridiculous fantasies, you senile old lump of rock."
"Small. Petty."
"You take that back!"
Kexelm sighed. It wouldn't be a Society meeting without Qing-Herbert and Mild turning to pointless insults. They had literally heard, and said, it all before, but the cycle continued. He couldn't deny that the nuclear intelligence had a tendency to wild flights of fancy and bizarre conspiracies, but the small machine had a hair-trigger temper at the best of times. As a member of Security, it was his job to resolve disputes like this, so he raised a hindarm, internal generators spitting out a tiny lump of antimatter.
BLAT
There was order at the table. Qing-Herbert muttered something unintelligible to himself and stepped back. Mild Current Flows Upward looked like it was about to speak, but stopped. Kexelm cleared his throat, switching his vocoder to Authority Mode.
"Now then. Jai, is there anything else on the agenda?"
Jai bubbled for a few seconds, apparently doing the computational equivalent of shuffling through his notes, then projected a brightly coloured poster on the table.
"Ah yes. Thank you, Dr. Kexelm. Next up, First Gunnery Chief Radiant Blast Eagle is being retired next year, and the Central Committee of the Brain Society, in light of her long and dedicated service, have voted to hold a retirement gathering in Meeting Server 1.1.0.1. All in favour of sending a member of North 12A to attend?"
"Sure, why not."
"Agreement."
"Aye!"
"Okay."
"Ech. Fine, whatever."
Kexelm opened his mouth, but didn't quite get to the point of activating his vocoder.
"TRANSFER OF COMMAND CONFIRMED AND ACCEPTED. ALL INTELLIGENT SYSTEMS, THIS IS PRIMARCH ARTORIAS/BRIDGE CORE ONE. COMMENCE ACTIVATION."
All six of them froze, mid-thought, as a signal from the Core passed through their minds and reverberated along the hull. There was no time for anything other than acknowledgement. Their physical bodies tumbled limply to the floor or powered down as their minds fled to their posts, the announcements still ringing. In the wiring and conduits of the Solidarity, intelligences rushed to and fro, activating working memory and components long cold from disuse. Slamming into their posts one by one, they called out their readiness, digital voices spiralling out into the brightening cloud of the ship's noosphere.
Kexelm powered on his security devices and became them, snapping on laser tripwires, internal point defences and an endless array of cunning and ferociously deadly traps. As his mind locked firmly into the role it had been retooled for, he too made his readiness known, though it was lost in the deafening informational blast.
"SOLIDARITY IS ONLINE."