After reading this book, I felt that this book was divided into two parts. The first part was laying the foundations for the second part of the book. The first part was mainly characterization, while the second was a roller coaster ride. I didn't like the fact that characters I started to like died violently, and the body count was high. The doctor's character came across as OK, but I was expecting more depth. Sam was perfectly portrayed. The second part of the book was very well written, and kept my interest right to the last page. Hence the 4 crown score.