[hasbot]

Google AI does a pretty good job of this already:

> I'm on page 750 of Anathem. Please give me a recap.

> You are currently reading the section of the book where the main characters have been launched into orbit aboard a repurposed military rocket and are preparing to board the alien starship, the Daban Urnud.

more recap details follow....

[tstrimple]

Given different printings and formats for books, I’d be very surprised if asking about a specific page number works reliably at all across books. I don’t even know if epub has page numbers embedded to keep track because the number of words on a page of an ereader is entirely arbitrary. My wife has her kindle in grandma mode or something. Only about 50 words fit on a page.

I would expect much more reliable results from chapter numbers though.