Pinhead- Plague Fog

The Priest had once again begun his preparation—an incantation of some sort—when Felixson began muttering an incantation of his own under his breath.
...
“[Y]ou can stop that wretched hobbling. We have a long journey ahead. A plague fog now waits for us a quarter of a mile from the city’s limits. It will ensure that the damned are off the streets and in their homes, if homes they have.”
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  And nestled amid it all was a greenish fog that sat, unmoving, in the expansive shantytown in a trench directly in front of the city. The fog cast its greenish hue onto a band of buildings from the monolithic structures close to the summit down to the high walls that marked the limits of the city proper as it sat, willfully motionless, over a portion of the mass of tents and crude shacks and animals that formed the chaotic fringe around the city limits. It was this place, this vast shantytown, that was the source of the screams. This bizarre fog had seemingly settled upon this place, and it was apparent that those who had failed to find their out of its haze were in terrible agony.

-The Scarlet Gospel, BOOK TWO, Chapter 12