Give me your best suggestions for a ‘fiendishly clever’ book

I don’t mind what the genre is, but I’m looking for a book that you’ve read and come away thinking ‘wow, that was really clever’. It might have been a jaw-dropping twist, the way the author made you feel
about a character or how they managed to weave so many intricate plot lines together. I want to read something that makes me think ‘damn, brilliantly done’. Thank you in advance for blowing my mind.