Icarus

Icarus was an exceptionally hospitable planet for humanoid habitation. According to pious legend, the original inhabitants were colonists transported to Icarus inside giant birds flying through space, by the Creator of Icarus. The same legend prophesied that one day the Creator of Icarus would come back for the colonists. 

But with the development of planetology, scientists scoffed at the legend. Planetology was the study of complicated things that give the appearance of having been designed for a purpose. Scientists dismissed the legend as a superstitious, prescientific etiological fable. 

That divided Icarians into two factions: scientists and fundamentalists. But as planetologists continued to excavate Icarus, they uncovered evidence that Icarus was an artificial planet, only a few thousand years old, composed of metallic alloys. 

Fundamentalists took their discovery as scientific confirmation that the legend was true. But scientists retorted that positing a Creator was a cop-out and science stopper. Appealing to external agency explains something mysterious by something even more mysterious–which explains nothing at all. We cannot allow an Alien Foot in the door. Anyone who could believe in terraformers could believe in anything. To appeal to a terraformer is to allow that at any moment the regularities of nature may be ruptured, that miracles may happen, through outside interference. 

Scientists accused fundamentalists of committing the little-green-men-of-the-gaps fallacy. They pointed out that planetology had an impressive track record of explaining things without recourse to invisible, extraicarian meddling.  

So there was yet another impasse between the scientists and fundamentalists. Then one day a giant bird from outer space landed on Icarus, and out stepped the Creator. Fundamentalists immediately took this as vindication of the ancient oracle. 

Scientists couldn't believe their eyes. Some of them said it must be staged. Others said a hallucination was more plausible than accepting the existence of a Creator. The Creator ushered the fundamentalists into the giant bird and flew away, leaving the scientists behind. A month later the climate-control machine in the planetary core wore out, and life on Icarus perished in a mass extinction event.