This post was inspired by a writing prompt in the Worldbuilding community - Worldbuilding Prompt #616 - Fallen Civilizations
Image created by AI in Nightcafe Studio
The small grey alien looked down at the world below him and sighed. Sooty grey clouds totally obscured the planet's surface, illuminated from below by occasional bright flashes.
He turned to his second in command, saying, "Well, it's time to pack this moonbase up, number forty three. The experiment is over. These - what did they call themselves - 'humans' - have failed the Great Filter. Their civilisation has fallen, they will all shortly be dead from self-inflicted causes."
Number forty three bowed his head in agreement. "It's such a shame. They had such potential, and their funny little ways were quite charming in a chimp-like kind of way."
"Never mind, it's done now," said the leader. "Report back to home that we will set the chrono-slip dial to fast forward. We can come back in ten million years and see if the cockroaches have built a better civilisation."
He watched impassively as number forty three started unplugging obscure devices and loading them into the flying saucer. When he went to unplug one appliance, the leader asked, "Why are you taking that ? Didn't you make it purely for the humans ? Anyway, it wasn't in our research brief. Why did you put so much effort into it ?"
Number Forty Three hesitated. "It took me so many experiments to get the degree of chill just right. I know it didn't serve any purpose, or give any useful data. But the humans seemed to expect it, and the expressions on their faces were such a delightful mix of pleasure and shock. It seems a shame to waste all that effort, but I guess we might as well leave it, no other species is likely to respond to the custom instruments it contains."
With the last of the other devices onboard the flying saucer, the aliens turned off the light and departed, leaving a single appliance plugged into the power socket in the abandoned base.
Image created by AI in Nightcafe Studio, slightly modified by me