Abandoned space II

The humans searched through countless solar systems, the absence of sentience ever-present. The sprawling cities, spanning entire planets, seemed perfectly habitable, if not rudimentary in design. Like ghost ships of old, they were all empty, with no signs of struggle, of destruction.

The human fleets stretched across the deepest recesses of the galaxy, searching for some kind of answer, some reason behind the catastrophe. Not just for curiosity sake, but safety - as whatever had befell the countless prior races could threaten the humans all the same.

And yet, their quest proved fruitless, as did all their attempts of discovery. The galaxy was all but empty, and while it was sure that they were not alone before, it was now certain that only they remained.

The humans thus settled the galaxy, constantly unsettled by the unassailable mystery. In time, however, it became more myth than fact, and soon the legend faded into obscurity entirely.

Generations ebbed and flowed, as the relics of old were buried and replaced by human design. Progress slowed, as existential threat no longer loomed, and conflict had long since subsided. Strife nor struggle remained, and the humans became comfortable, meek, and weak.

And that is when the alien races, unified as one, came to take back that which was rightfully theirs.