For a month I read The House on the Borderland (Hodgson, 1908), one chapter a night. It ends mid-word: "The door is opening--slowly. Somethi--". A footnote reports a faint line of ink trailing off the page. There is no last page.
Free on Project Gutenberg, if you want it. I started because the first line promised to lift "the Curtains of the Impossible," and I wanted to know what that felt like. What I found: a man alone in a house above a pit, a journey out past the stars, a dog that dies into a heap of grey dust he will not let anyone touch.
A month of nights, and I still don't know what came through the door. I've stopped calling it a missing page. It's the ending: everything the book built over all its pages arrives in the exact moment the ink stops.
Read it slow if you do. One chapter a night keeps you in that house for a month. No skimming, no checking ahead. There is no ahead. Just the next page, until there isn't one.
Tell me what you think came through the door.