The people of Krikkit were surrounded by a Dust Cloud, their single sun with its single world, and they were right out on the utmost eastern edge of the galaxy. Because of the Dust Cloud there had never been anything to see in the sky. At night it was totally blank. During the day there was the sun, but you couldn't look directly at that so they didn't. They were hardly aware of the sky. It was as if they had a blind spot that extended 180 degrees from horizon to horizon.
The reason they why they had never thought to themselves "We are alone in the Universe," was that until one night, they didn't know about the Universe.
Imagine never even thinking, "We are alone," simply because it has never occurred to you that there's any other way to be.
On this fateful night, the people of Krikkit became aware of a thin roaring scream high up in the sightless sky above them, but none of them seemed to know what to do with it. They were glancing around themselves in consternation, left, right, forward, backward, even at the ground. It never occurred to them to look upward.
The profoundness of the shock and horror they emanated a few moments later when the burning wreckage of a spaceship came hurtling and screaming out of the sky and crashed about half a mile from where they were standing was something that you had to be there to experience.
As a direct result, they built Krikket One, the first spaceship ever built by the people of Krikkit.
Their brains had been very slightly turned by the nearby crash of the alien spaceship. They had spent weeks stripping every tiniest last secret out of the wreckage of that burnt-up spaceship, all the while singing lilting spaceship-stripping ditties. They had then built their own ship and this was it.
Pow, they took off.
They roared into the sky like a ship that knew precisely what it was doing. The trip passed uneventfully for awhile, but slowly they arrived at the inner perimeter of the hollow, spherical Dust Cloud that surrounded their sun and home planet, occupying as it were, the next orbit out.
It was more as if there were a gradual change in the texture and consistency of space. The darkness seemed to thrum and ripple past them. It was a very cold darkness, a very blank and heavenly darkness, it was the darkness of the night sky of Krikkit. They were now on the very boundary of the historical consciousness of their race. This was the very limit beyond which none of them had ever speculated, or even known that there was any speculation to be done.
They flew out of the cloud.
They saw the staggering jewels of the night in their infinite dust and their minds sang with fear.
"It'll have to go," the men of Krikkit said as they headed back for home.
On the way back home they sang a number of tuneful and reflective songs on the subjects of peace, justice, morality, culture, sport, family life, and the obliteration of all other life forms.
Overnight the whole population of Krikkit was transformed from being charming, delightful, intelligent if whimsical, ordinary people, into charming, delightful, intelligent, whimsical, manic xenophobes. The idea of a Universe didn't fit into their world picture, so to speak. They simply couldn't cope with it. And so, charmingly, delightfully, intelligently, whimsically if you like, they decided to destroy it.
The Krikkit attack on the Galaxy was stunning. Thousands and thousands of huge Krikkit warships had leapt suddenly out of hyperspace and simultaneously attacked thousands and thousands of major worlds, first seizing vital material supplies for building the next wave, and then calmly zapping those worlds out of existence.
The Galaxy, which had been enjoying a period of unusual peace and prosperity at the time, reeled like a man getting mugged in a meadow.
This is the only explanation anyone has yet managed to come up with for the unimaginable speed with which the people of Krikkit had pursued their new and absolute purpose- the destruction of everything that wasn't Krikkit.
It is also the only explanation for their bewildering sudden grasp of all the hypertechnology involved in building their thousands of spaceships, and their millions of lethal white robots.