Damn, I was NOT expecting this to be all that intense! I read the story in my science fiction class, I wasn't very disturbed by the book at all because it didn't really describe anything but this- THIS is what I needed to be terrified! Horror stories need to be VISUAL and DETAILED in order to get the feel of the genre, after the mom and son got hit by lightning, thats when I got a bit traumatized. In the book, it never really mentioned the mom and son mutating together (or it did and I just wasn't paying attention) but the other stuff, like the crops going bad, it did mention.
Overall the ending left me shook, I do recommend this but please, if you get disturbed easily- this is not for you, but horror cravers like me, go ahead, grab some friends, and enjoy what this movie has to bring!