For those of you who dont watch the series, Sam and Dean Winchester are brothers in a family of demon hunters. Their mother was killed by one when the brothers were still children, and the dad, John Winchester, has been trying to hunt down that demon ever since. The brothers were trained by their father as if they were military soldiers, even at their young age. Now, the brothers are elite hunters, and they hunt down spirit, demons, and other paranormal things, while the dad is going solo, trying to find the demon that killed their mother.
The book itself, however, is about Sam and Dean going on vacation to the Grand Canyon. They never expected that anything would happen while they were there, but....shit happens. Apparently, there has been a vast amount of strange and brutal murders every 40 years in the small town just beyond where the Grand Canyon lies. Cedar Wells, the unfortunate town, has not only one spirit/demon coming to kill the people, but a whole group of deadly spirits. The spirits were resurrected from a long time ago, during a period in which mass murders occurred. All the humans AND animals were revived, and can only kill other people the same way they were killed before they died. There are some shapeshifters, too.
But that's not even the half of it. Right in the center of the one week when the killing sprees start (wouldn't you figure) a mega-mart is announcing it's grand opening right in Cedar Wells. That should bring loads of people from out of town to experience death first-hand. Once the killing spree sarts, then no one can leave the city's boundaries, or else they'll die.
Another thing really epic about this book is that, since the killers are spirits, then they can materialize right in your face if they wanted to, and conventional bullets dont do shit against them.
This is definitely the best book I've ever read. I'd suggest it to any sci-fi lovers, and I strongly suggest it to anyone who likes the T.V. show. Gimme some feedback - I want to hear other people's opinions on the book. IF anyone else has read it, that is.