Have you ever read a book that scared you so much you either couldnt finish reading it or just had to finish reading it?

I started listening to a book on talking cd called The Book of Lost Things by John Connolly. I cant get passed the 3rd cd because it is really creepy and unsettling. Partly it may be because it is on spoken word format but I am pretty sure that it would still deeply freak me out if I were reading it myself. It is a fantastic fantastic story but I cant handle it!! A sign of a great writer perhaps.

What book has genuinly frightend you or set you on edge? Have you ever been really stirred up by a book?