The war against Voldemort is not going well; even Muggle governments are noticing. Ron scans the obituary pages of the Daily Prophet, looking for familiar names. Dumbledore is absent from Hogwarts for long stretches of time, and the Order of the Phoenix has already suffered losses.
As in all wars, life goes on. Sixth-year students learn to Apparate - and lose a few eyebrows in the process. The Weasley twins expand their business. Teenagers flirt and fight. Classes are never straightforward, though Harry receives some extraordinary help from the mysterious Half-Blood Prince.
So it's the home front that takes center stage in the sixth installment of the story of Harry Potter. Here at Hogwarts, Harry will search for the full and complex story of the boy who became Lord Voldemort - and thereby find what may be his only vulnerability.
The darkest and most unsettling installment yet. It is a novel that pulls together dozens of plot strands from previous volumes, underscoring how cleverly and carefully J. K. Rowling has assembled this giant jigsaw puzzle of an epic -- the achievement of the Potter books is the same as that of the great classics of children's literature, from the Oz novels to The Lord of the Rings: the creation of a richly imagined and utterly singular world, as detailed, as improbable and as mortal as our own.
- Michiko Kakutani, The New York Times