I love books that keep you guessing. Just when you think you know the answer—clack!—the trapdoor opens, you fall another level deeper and realize you didn’t even know what the question was.
But the best puzzle box books aren’t just the ones that surprise you. They’re the ones where the answer was dangling in front of you the whole time, like the magician who buries the reveal in the box hanging over your head, if only you could see through its gearworks to the truth inside.