"You do not understand," it says. "To stop being what we are would be like stopping the tides, or ending the flow of the seasons. It cannot be done. Not without great devastation. We are as essential and natural to this place as the moon is to the earth."
"I don't know if that's true," you point out. "There are plenty of places that do just fine without…something like you. Most would say they're a lot better off because of it."
"We are not there," the Fog Beast says. "We are here. Those who are afraid of a flood should not live by the water. Those who are afraid of having to pay the price for their wrongs should not live here. We will return once three nights have passed. All is not right in Arbor Isle. So many of you live immorally, even knowing that we are here, watching and growing stronger with every wrong committed. We will set things right. No matter how long it takes."
The fog withdraws from you completely, like a movie playing in reverse. Thin tendrils drag behind the dense cloud like the train of a tattered wedding gown, and the air smells like long-rotten fruit in its wake. As it retreats deeper into the woods, its many faces still observe you with unblinking eyes.
Your mouth is as dry as bone. You have three nights.