harry potter and the half-blood prince.
Released on July 16, 2005 after a two year wait, Harry Potter and the Half-Blood Prince followed in the footsteps of the previous books in the series, shattering records with its sales: the print run in the US consisted of 13.5 million copies, 6.9 million of which were sold within the first 24 hours of release. An unprecendented amount of security surrounded the release of the book, prompting J.K. Rowling to obtain a court injunction to keep the plot and details of the book under wraps until the book was sold to the public.
As Harry Potter enters his sixth year of school at Hogwarts, chaos is taking over in both the Muggle and Wizarding worlds. A new Minister of Magic, Rufus Scrimgeour, has come into power and he's determined to have Harry act as a mascot for the Ministry. Meanwhile, Harry has a new teacher to contend with at Hogwarts, as well as his N.E.W.T. classes (though he gets a bit of help from the mysterious Half-Blood Prince in one of them), which involve even more homework than in the past. Also occupying his time are private lessons with Dumbledore and his new duties as Gryffindor House's Quidditch team captain. And romance is all around at the school, with contraband love potions from Weasley's Wizarding Wheezes popping up everywhere, and crushes between classmates have become commonplace. Most importantly, knowing that Harry must prepare himself to eventually face Voldemort, Harry and Dumbledore explore Voldemort's past in an attempt to discover a vulnerability with which to defeat him.