It's one of my favourite books - just chilling. The writing skill in switching partway from first person nutter to first person young articulate girl is astonishing. Aother of my favourite books (I have rather a lot ) is The Magus by John Fowles - the sort of book you keep thinking about afterwards.
Just re-read it a couple of weeks ago - I read it for the first time when I was about 18 and thought that the girl in it was just like me - I have this really overblown entry in my diary where I'm raving about it - exclamation marks and omigods all over the place.
I read it again to see what the girl seemed like to me now I'm 35, and I have come to the conclusion that I must have been a right pretentious PITA back then!
I love the way he writes the different characters - still found it very creepy, and found myself trying to puzzle out possible escape plans that might have worked.
I found the jump between the two characters really good and how the nutter only spoke of her and his feelings for her and she only spoke of the man she was in love with - with very little regard or comment about her captor!