I found an interesting feature. In Russian localization, the content of this note has a diametrically opposite meaning. It says something like this:
To High Priestess Eshinimma,
Although we appreciate your concern, we cannot recommend any one of the methods that can offer kuliltu. As far as we all know, they themselves may be the cause of this pathogen.
One could assume that this is a localization error, but the remark about the connection between Rusalki and pathogen came from nowhere. In addition, there is no "Plan B" note in the Russian localization at all. Instead there is a note "Unfinished letter", which probably contains an additional monologue of Veruska. Perhaps the story complements itself in different localizations?