This is part of the marketplace item (see below) .... I don't see where these overlays are or how to use them, I am missing something or are they just not available on roll20? The Scarlet Citadel includes many areas that change during play
or that contain secrets characters must work to reveal. These are
represented on map overlays. When conditions change or when characters
trigger a secret revelation, place the appropriate overlay on the map.
The illustration below shows how the overlays work in conjunction with
the large poster maps to create new conditions within the dungeon
levels.
