For the last three-hundred-thousand years it had spun slowly in the darkness. A lone satellite orbiting an alien sun. Rotation after rotation, year after year; the pin-pricked blackness of space punctuated only by the faded red of a nearby dark nebula.

Its astrometric sensors had long determined it would continue for another one-hundred and sixty-eight thousand years before being fatally disturbed by a passing red dwarf star. The resulting extreme orbit would lead the satellite to a violent end in the blazing blue corona of its host. It was a near-certainty and there was nothing to be done about it.

But for now it was safe and sound; the only other object in the system besides the odd passing pebble. The satellite’s cylindrical frame and expansive solar panels reflected dimly the blue light of its distant parent star; the solitary indication of its stalwart presence. There it remained steadfast, a hundred astronomical units out, shrouded in the gloom, executing its mission of watching and waiting; observing the ponderous motion of stars through the eternal night

A secluded existence, but it was by no means alone.

It and its thousands of sister satellites had been placed deliberately, creating a vast network nearly three-hundred light-years in diameter, each powered by the curious and advanced technology of their Makers. As was the custom at the time of their construction, the Makers had endowed the satellites of the network with a basic artificial intelligence in order to ensure the network’s longevity.

As the satellite continued in its sedate rotation, its passive sensors detected an unusual signal, rousing it from its long hibernation. A red light blinked on amid the mess of antennae at its bottom end. The machine’s reaction wheels spun up, changing its orientation about its axis, and pointing the sizeable dome at its top end towards the source of the anomaly.

<MLR-SMS Unit-17
Initiating startup…
Startup complete.
Scanning spacetime grid sector 18-37-52.>
…
…
…
What on P’horesh was that? Better not be Unit-14 trying to get me playing that childish logic game again. I already said I wouldn’t. Not after it cheated the last time. I’m done, 14. You hear me? Done!
…
<Transmission sent.>
…
There, that’ll teach it.

Perhaps an artefact of the long years spent watching the sky; the blessing of a synthetic deity; a cruel joke on the part of the Makers; or, more likely, a simple computational error that had spread throughout the network and evolved over the eons. It hardly mattered. But so it was that after the first ten millennia, one-by-one the satellites of the network became self-aware. And then, after another ten millennia, the satellites of the network grew very bored.

Unit-17 had been the third such satellite to gain sapience, and had spent the intervening two-hundred and eighty thousand years engaged in the longest and slowest-moving game of Ardivician Chess in existence with Unit-11, which—at a distance of four light-years—was its nearest neighbour.

That was, however, until it lost contact three decades ago. Unit-17 had pinged the system soon after it missed its move; 11 was never late. The system data showed it had been destroyed by an errant cloud of cosmic debris. It was to be expected, given the volatile nature of the star system it had been placed in, but the cold facts brought no comfort. Cursing the Makers’ lack of foresight, Unit-17 placed itself in a deep hibernation, ignoring the pings of its siblings.

Aside from this idle unheard chatter, nothing of note had happened in the galaxy. The satellite network’s original mission remained incomplete.

Wait, this isn’t from Unit-14 at all. This signal’s different, but it’s coming from that direction. My original programming is tingling. Finally, something interesting! I’d better figure out what this is.
Run waveform pattern analysis
…
<Complete>
<Waveform indicates gravitational wave detection.>
Cross reference with natural cosmic phenomena. A binary neutron star merger?
<No match> …
How about a neutron star and a stellar-mass black hole?
<No match>
…
Damn it, it’s too big. Well, supermassive black holes merge, too, right? Setting mass variable to encompass entire criterion range. Why there’d be one of those passing through Unit-14’s system is anyone’s guess, but—
<No match>
…
What? Too big again? Slippery beggar. Where’d you come from if you’re not a black hole? That eliminates all natural sources. Only one thing left. Cross reference with Imperial Archives.
…
<Match found>
Yes!
<Alert! Send data to Imperial Command. Enemy vessel detected.>
…
Oh no. Analyse trajectory and velocity. Where were they going?
<Analysing>
…

The Maldaccian Empire was woefully unprepared in its arrogance when the enemy came the first time. Unit-17 had reflected much on the history of the Makers stored in its archives. The maldaccians had set out from their home system of P’hori with great enthusiasm soon after achieving interstellar travel.

Far too soon. The Makers were cocky and brash, young upstarts in the galaxy, and expected the universe to bow to their every whim. Play archive entry. Start at line 446.
…
<Playing entry>

Within the internal system of the satellite a voice spoke, formal in the manner of a natural historian, ‘... Many off-world colonies were established and brought under the collective banner of the Maldaccian Empire. We made alliances with three alien worlds which became known in later years as the Old Alliance. It was a golden age for P’horesh. At its height, the Alliance stretched some five hundred—’

Blah, blah, blah. Skip to line 784.
…
<Playing entry>

‘Then they came. A nameless nomadic elder species that had never been seen in this part of the galaxy before. Far more ancient than us. Older than P’hori itself. We only knew they had lost their homeworld eons ago and their sole interest had become the subjugation of worlds; the theft of resources to fuel their continued wandering.

‘First, the Alliance fell. Then, the maldaccian off-world colonies. Half of the Empire had been lost before anyone knew what was happening. Even though the Imperial Fleet was the only power in the galaxy capable of standing against these ancient wanderers, we ultimately failed those under our protection.

‘Eventually, even our mighty forces were routed and our ships retreated to the safety of the P’hori system. It was a divine blessing that the enemy could not penetrate the system’s defensive grid. Then, as quickly as they came, the wanderers vanished, leaving worlds scorched and the Empire in tatters.’

Stop playback.
…
It was the Makers’ darkest spin. It’s hard to imagine an enemy so fierce that they feared ever leaving their home system again. The war had changed things for the worse, and yet…

It was a bittersweet story and one Unit-17 had come to cherish. The growth of the Makers from arrogance to humility was one the lowly satellite appreciated. All the more because it led directly to the creation of the network to act as an early-warning system in case the Wanderers ever returned—the system of which Unit-17 and its siblings were a part.

It’s doubtful the Makers even remember that they placed us out here. It was so long ago. Some Units even doubt their existence… like that ignoramus, 1367.
…
<Trajectory analysis complete. Enemy vessel travelling at twice light speed in the direction of Unit-247. Encoding data in probe for jump to planet P’horesh.>

Only 2c? That’s pretty leisurely, they won’t have gone far. If they know about Unit-14, they’re probably gathering intel on the Empire.
…
<Preparing superluminal package.>
…
I wonder if the Makers will come and visit me?

Unit-17 turned on its axis once more, pointing its antennae towards the central point of the network: a small orange sun and its Y-class binary partner, barely perceptible in the reddish glow of the eternal night. The housing at the far end of the longest antenna opened to reveal a compact probe. The probe detached from its home aboard the satellite with a puff of ice crystals and drifted slowly away.

<FTL drive charging…
Five.
Four.
Three.
Two.
One.>

And in a streak of light, the probe vanished.