If you are a fan of either Frank Peretti or Ted Dekker I'm afraid you will be disappointed with this one. I've read all of Peretti's and this was my third by Dekker. I didn't care for this one at all compared to how well I liked their previous works.
The book very quickly begins making no sense at all and is completely removed from reality. Many of Peretti's earlier works may seem completely implausible by some, but atleast the roots of the stories were based in reality. This one is absolutely not realistic. It plays out like a cheap Hollywood horror movie and I was as irritated with the characters of the book as I am with characters in these movies. Their actions are the exact opposite of what anyone with any sense would do.
The story just seems thrown together to me and not very well thought out. I did finish it, but I can't say I'd recommend it. Very disappointing considering that both of these authors are capable of much better.