I personally really enjoyed the book. Slight Spoilers ahead, as others say about the ending, yeah it is abrupt and quick. I liked it though, I thought it was a good example of how you can search and search for answers and not always find them or die trying. Not every book has a happy ending! I kinda assumed what would happen at the end and I was right. I haven’t read any other books by this author yet and that may be why my view is different. The only complaint I would have is that I wish the idea behind the whole first and second sleep thing was explained.