Overall, I liked this book. The story was well-crafted and engaging. I really liked how the authors explained radioactivity and radiation poisoning in a way that is understandable.There was one element I did not like...[Spoiler]The whole storyline about Isabelle and her ties to Nagasaki were the part that I feel was over the top. I have no doubt authors as good as these two could have come up with a motive that did not feel so contrived. It pulled the book down and made it less believable.[End Spoiler]