The first few chapters are such plodding exposition I forgot what kind of book I was reading. Fortunately things pick up. In fact, it changes gears so abruptly, it felt like two different books... I momentarily wondered whether this was some kind of intentional metafiction device.
I saw "the twist" coming from miles away, looong before the halfway mark, but it was still enjoyable seeing how we'd get there.
More like 3.5 stars than 3.