Rating: 5/5
I bought this book because a bookstore's cafe had this cute "buy a coffee, buy a book for $5", and it was a good use of $5.
This book is explicitly an expansion of Poe's Fall of the house of Usher, but using a 19th century-flavored natural philosophy plot. If you've seen the cover, it does involve fungus.
The reviews and book stubs I saw talked up horror and description, but maybe since I've read so many similar plots I mostly felt this fun and nostalgic. It's a good book, took maybe a day or 2 to finish, and has some fun, well written characters and a neatly resolved plot. This is apparently has a sequel involving the main character, a sworn soldier (in the internal world building, a kind of distinct social role for women taking on the masculine-ish, formal role of a soldier or officer), and there a good character.
I don't have anything to say against it, it was fun, well worth what I spent on it, and I had a good time with it sticking in my head