Dean Koontz makes it hard not to compare him to Stephen King, because it seems like that's where he gets his ideas. The difference between them is in the depth - of the characters and of the web of evil in which they become entangled. While almost every King book seems epic in these qualities, Koontz's seem like a pale shadow. A lot of reviews hail this book as the return of Koontz at his best - if that's the case, I'm not in any great hurry to catch up on those that I haven't read yet. I'll say it again - what makes a horror book terrifying is an intense connection with the characters to which the scary things are happening. King is a master at this, Koontz is not.
That said, this book in particular isn't bad or anything. The story is interesting enough, but it was hard (for me at least) to relate to the characters. Do families so perfect even exist? Koontz's attempt to juxtapose great evil with perfect innocent goodness creates a situation that rings false and even stereotyped at times. There were scattered paragraphs of near-philosophy in this book that sometimes broke up the pace just enough to jar my mind away from the story. Despite these flaws, however, I did continue reading with much curiosity. The ending was satisfying, if a little cheesy.