A Signature in the Periphery - Part Two

Looking back at certain moments in the Alchemist Camp, you would probably feel an indescribable sense of dissonance.
As if something were constantly clinging to the edge of the world, only willing to show its face in your peripheral vision.
The more you tried to see it clearly, the more it would seem to be erased by something, only to stubbornly continue reappearing.
—When the alchemist Flavia went out to gather materials, it appeared in the sky, in a pattern momentarily formed by a flock of birds.
—In the crystals refined by the alchemists, it rested on that unknown dark crystal, its patterns too clear to have formed naturally.

What on earth was it... It seems to have influenced my memories, as if even the memories themselves have begun to succumb to the uncertainty.