I was so excited to read this and was just disappointed. The story starts off eerie and suspenseful and then just plateaus. At around page 200 I thought we were finally being told the back story that would take the story in a different direction, but all it did was tell us the same story over and over of how the strain spread from one person to another. It told us how it happened to every character. Completely overkill and to me assumes that del Toro didn't think his readers could figure out the grand scale of it spreading for themselves. I really wanted to like this book and gave it so many chances, but I just didn't like it. As an aside, I loved Pan Labyrinth which was a large factor in reading this.