Just finished reading it. I agree with you, it's a great book, and the ending was, indeed, unexpected!
'The dark half' by Stephen King, almost finished the book. The last books I read also were Stephen King's, I like how the stories go, it's unexpected every time. Loved 'Cujo' and 'The Institute' particularly (Running man was good too) !
'Father, look at this. DO SOMETHING!'