Challenge: Scariest Book

This is part of the Wednesday Weekly Blogging Challenge over at Long and Short Reviews. (The first link will take you to the list of topics; the second one goes to the homepage, where you can find a post with everyone's responses each week. Feel free to join in!)

This week's prompt is "scariest book I've ever read", just in time for Hallowe'en. 

...Which is tricky, because back in my youth and particularly from about age 12 to age 16, I read a lot of Horror. Stephen King, Dean Koontz, any number of unknown or less-known authors... and some older stuff, like Lovecraft. I have no idea what, out of all that and all the books I've read since then, would qualify as the scariest. 

On top of that, I remember some scenes and moments that came from books whose authors and titles I no longer recall. It's like having the ghosts of books in my head. 

There was a werewolf book which I remember as being interesting but not especially striking, except for one scene where the heroes have encountered the werewolf and are fleeing from it in a car. The driver of the car is so freaked out that he won't slow down, he just keeps trying to go faster and faster while the other characters are trying to get to ease back to a safer rate of speed. 

Until one of them looks back and werewolf is right behind them. 

Not a great book, as I said, but that particular moment hit me as a visceral shock. 

There was the book where the two protagonists got sucked into investigating the remnants of a corporate bioweapons program. The monsters were interesting enough, and there was a very obvious wish-fulfillment element early on where the hero, an Ordinary Guy, stumbles into a relationship with the heroine, a movie star (possibly while humming Uptown Girl under his breath). But the really memorable scene comes before the confrontation with the monsters, when our hero visits one of his old friends who used to work for corporation... and discovers that the friend is now bedridden because he's been exposed to something that rendered all his bones cartilaginous; he barely has enough body structure left to breathe. 

Then there's a moment in Barbara Hambly's Darwath books (a truly excellent if somewhat older portal fantasy) where two of the characters have gone to investigate the nearest nest of the monsters only to discover that A) it's still inhabited, and B) they've been cut off by the arrival of a band of raiders in the entrance to the valley. They're climbing out one side of the valley when they look back and notice that the whole valley floor has an odd set of patterns: lines and shapes in the trees and grasses that are only visible from above. The heroine, a historian by training, identifies the effect as being caused by the buried foundations of some ancient city, and suddenly they realize just how long these things have been preying on humanity. 

So... scariest book? I don't know. But there are three of my favorite moments, even if I can't recall exactly whence two of them came.