Yesterday, I had the opportunity to visit Book Passage in the evening. The back building was quite empty. A couple of workers, a lady studying Italian - and myself. The lady left. It was just me. I had the whole bookstore to myself. It was kinda fantastic.
I picked up a book titled How to Write a Page Turner.
The first chapter is about Danger.
It gave an example of a guy in the woods that would abuse his daughter physically. Though she grew up with constant threats and probably didn't know better - the audience knew it was wrong. As readers, we'd be put on edge knowing what has happening was different -- dangerous -- and this causes us to keep paying attention; to find out what happens; to turn pages.
We'll be flipping pages. What happens next?
What does he do to her?
What does he force her to endure?
How does he do it?
How does she respond?
Because she is a member of our species, we subconsciously want this information in case something similar happens to us. We're learning creatures and 'danger' shouts at our brain - "Hey! pay attention. You may need this information at some point."
We turn the page. Our brains are being spoken to on a primal level. Our lizard brain has picked up the signal and is on full alert.
If you want people to keep reading, insert an element of danger.