Shuttered book store at the bottom of a grassy hill on an island just off the shore of Thrushmoor.
In Chapter 39, the party examined the structure more carefully and eventually Rony broke in. Clearly, it once held a lot of books, but it was empty and abandoned when the party explored it. Dora felt the psychic residue of someone who was told this place would fail, but it succeeded anyway (for a time, at least).
First Reference: Chapter 37
Other Notable References: Chapter 39