Every civilization that wishes to survive has to follow one rule: stay quiet.

Stay in your system, improve your technology and do everything you can to not attract attention. If you need to expand then do so slowly and with specialized FTL engines so no one can scan for your movements.

They will know if you break the rule.

No one really knows what they are but the pattern is very simple: a civilization does something to attract attention and, in a few hours, it is gone.

All attempts at defence have proven useless, even the oldest and mightiest of the known empires don’t dare challenge whatever horror lurks in the starless void. Doing so only ever leads to destruction.

Civilizations are not heartless, however. Every time a new fledgling species is found the nearest advanced people give them a small whisper of information. It is risky and no one is forced to do such a thing but almost all sapients do it since they too were small once.

What happened when Gaia started transmitting messages to the void was quite the standard procedure: A type 2 intercepted the message, blocked it so no one else could hear it, and then whispered back how the natives should stay quiet and why.

Their duty was done and it was up to the primitives to either listen to the advice or perish.

Much to the delight of Gaia’s neighbour the messages soon stopped coming.

A few parties were made in celebration of successfully saving another species from total extinction.

After 10 years the parties ended.

After 30 the primitives were just small talk for most people.

After 100 only a few scholars and curious students ever learned about that event.

After 500 the only evidence that they had helped anyone was on old decaying servers.

Then something happened.

There, on the spot where that pale blue dot stood, a new message appeared.

And it was big.

A gigantic signal beamed throughout the void like a sun washing its light over a dark forest.

The message might have been on an untranslatable language but its meaning could be understood by all.

“Come and get some”

Only a few minutes after the message washed over the quiet galaxy the entire void changed.

Gigantic ships which were once hidden and waiting for prey emerged from the edge of blackholes and the depths of planets and asteroids. Entire stars and planets which were once thought to be part of common solar systems revealed their true identity as war machines of unimaginable scale.

And they were all headed to one place.

The entire galaxy watched in awe as the beasts that controlled almost the entire void marched towards their prey.

But then they stopped.

And one of them imploded on itself.

Then another.

Then ten thousand more.

If the galaxy was in awe before, now they were in sheer disbelief.

There, on the interstellar void between Gaia and the rest of the galaxy, a truly gigantic fleet stood against the great monsters. Both sides fought fiercely as the unstoppable force of the void clashed against the seemingly unmovable defence of the Gaians.

And there they stood, two titans clashing in the void while the very fabric of the galaxy bent under the pressure of the battle.

By the tenth year of fighting, however, the monsters slowed down. It was a small difference but it just kept growing.

By the fifteenth year the Gaians were destroying two enemy ships for every one they lost.

By the eighteenth year it was over. Gaia had won.

The other civilizations stood in stunned silence.

Some were too scared to attract the attention of this new predator. Some were quietly making plans to serve their new overlords. Most were just too shocked to react.

Another message came through, this time it was written in all sapient languages:

“Sorry, we don’t like the quiet”

=======================

By /u/Mercury_the_dealer on /r/HFY