Harry Potter and the Half-Blood Prince

Harry Potter and the Half-Blood Prince is a fantasy novel by J. K. Rowling and the sixth and penultimate book in the Harry Potter series. It takes place during Harry's sixth year at Hogwarts and reveals events from the early life of Lord Voldemort while preparing Harry for the final battle against him. Bloomsbury published it in the United Kingdom and Scholastic in the United States on 16 July 2005.

It sold almost seven million copies in the first twenty-four hours after release, a record that was then broken by its sequel. There were controversies before and after publication, including copies delivered before the release date in Canada. Reception was generally positive, and the book won several honours, among them the 2006 British Book of the Year award. Reviewers noted a darker tone than its predecessors, with some humour retained.

The novel's structure is unusual for the series because much of it is investigation: Dumbledore takes Harry through memories in order to establish what Voldemort has done to survive, and the school year proceeds around that work. That investigation is wrapped around an ordinary school year: Horace Slughorn is persuaded out of retirement to return as Potions master, and one of Harry's fastest routes into Voldemort's history turns out to be an old annotated textbook he finds in a classroom.