I've been doing a lot of reading lately, and I'm currently working my way through A Matter of Class by Mary Balogh. It's billed as an Arraigned Marriage story with an Unexpected Twist! I was pretty sure I knew what the twist was by page 55. I'm on page 111 right now, and so far I've seen nothing to suggest that my guess is wrong.
If I'm right, it's not an Unexpected Twist! so much as a cheap writer's trick. The kind that you can only get away with once in your writing career. I used mine back in high school. M. Night Shyamalan used his with The Sixth Sense. Done well it can be tremendously effective. Unfortunately, these kind of tricks are often not done well, in my opinion.
The book is only 190 pages (in hardback, at hardback prices! I got mine at the library), so I expect to know if I was right or not by bedtime. I'll let you know. If I'm wrong, many apologies to Ms Balogh. But at this point, I really doubt I'm wrong.