An Incident in the Fog

Exploration Stage: Knowledge Archive
From: Eleanor
Description: The fog that has crept in from the city is probably the cause of the recent abnormalities. I tried to dispel the fog, but the anti-fog crystal didn't work. I need to reexamine the crystal. Could you bring it to me?
Completed: According to the crystal's analysis results... No way, that can't be true. I thought maybe it had lost its power, but it seems the fog itself isn't affected by the crystal. Why is that?