DarkMist

Overview

This mod introduces an invisible monster called the Dark Mist. It won't attack you, but that doesn't make it any less deadly.

Hint 1 (Spoiler):

Pay attention on your way back to the main entrance! Did anything change?

Hint 2 (Spoiler):

The Dark Mist will occasionally close doors between you and the main entrance.

Hint 3 (Spoiler):

Doors won't close if you're near the main entrance.

Hint 4 (Spoiler):

Doors won't close if you're not alone.

There's several ways to configure the frequency that the Dark Mist targets players. Note that there are some spoilers in the config files though.