You make a library with a bunch of bookshelves. Whenever you walk up to one, you can press an invisible button which will show a popup with a passage of one of the books. However, one of these bookshelves will result in you pulling a secret lever by accident hiding the bookshelf prop revealing a teleporter for a secret room!
I know it’s kind of long winded and requires a lot of writing, but I think It would be worth it.