Harry Potter and the Half-Blood Prince: 6/7 By J. K. Rowling

Half-Blood Prince is easily one of the better books in the Harry Potter series, though each is a masterpiece.
But the 6th installment of a 7-part series is bound to be full of great moments in the story.
There remains a great deal unanswered in this book, however, and the 7th will surely need to be no smaller than an average encyclopedia.

Harry Potter and the Half-Blood Prince: 6/7 By J. K. Rowling