Really enjoyed it. Quite a lot to think about — the ideas inside, the world-building, all the details and background information that you need to gather together and attempt to complete a puzzle.

Was really hard to put away at times, the pacing is quite good, and multiple points of view were masterfully ordered in a logical way.

Would need to think more about how would I rate it, and maybe write a spoilery review, but not sure I would do this. We'll see!