When I was trying to extract as much meaning out of George Eliot's Middlemarch as I could, I would read a chapter, and then upload that chapter's text file (thank you Gutenberg) to NotebookLM. I'd then have it extract unusual vocabulary words, Latin phrases, and cultural/historical references and compare that list to my handwritten notes from my close reading session. It was fun to have a dialog with the LLM about the chapter, and I felt like I got a lot out of it.

At some point I'll work on better integrating Emacs's nov.el EPUB reader with gptel to approximate something like this. Books are text, and I already have the ultimate text processing environment that I've invested quite a lot of time in.