Harry Potter and the Half-Blood Prince

Harry Potter and the Half-Blood Prince, released on 16 July 2005, is the sixth of seven novels from British author J. K. Rowling's popular Harry Potter series. Set during Harry Potter's sixth year at Hogwarts, the novel explores Lord Voldemort's past, and Harry's preparations for the final battle amidst emerging romantic relationships and the emotional confusions and conflict resolutions characteristic of mid-adolescence.
The book sold three million copies in the first 16 hours after its release, a record at the time which was eventually broken by its sequel, Harry Potter and the Deathly Hallows.

Plot introduction

Throughout the five previous novels in the Harry Potter series, the main character, Harry Potter, has struggled with the difficulties that come with growing up and the added challenge of being a famous wizard. When Harry was a baby, Lord Voldemort, the most powerful, evil wizard in living memory, killed Harry's parents but mysteriously vanished after trying to kill Harry. This results in Harry's immediate fame, and his being placed in the care of his muggle (non-magical) Petunia Dursley/Aunt Petunia and Vernon Dursly/Uncle Vernon.
Harry enters the wizarding world at the age of 11, enrolling in Hogwarts School of Witchcraft and Wizardry. He makes friends with Ron Weasley and Hermione Granger, and is confronted by Lord Voldemort trying to regain power. In his second year, several attacks on students take place at Hogwarts after the legendary "Chamber of Secrets" is opened. Harry ends the attacks by killing a Basilisk and defeating another attempt by Lord Voldemort to return to full strength. The following year, Harry hears that he has been targeted by escaped murderer Sirius Black. Despite stringent security measures at Hogwarts, Harry is confronted by Black at the end of his third year of schooling and Harry learns that Black was framed and is actually Harry's godfather. Harry's fourth year of school sees him entered in a dangerous magical competition called the Triwizard Tournament. At the conclusion of the Tournament, Harry witnesses the return of Lord Voldemort to full strength. When the next school year begins, the Ministry of Magic appoints Dolores Umbridge as the new High Inquisitor of Hogwarts. After forming an underground student group in opposition to Umbridge, Harry and several of his friends face off against Voldemort's Death Eaters, a group of Dark witches and wizards, and narrowly defeat them, though Sirius is slain in a rescue attempt. In the battle's aftermath, Dumbledore reveals Voldemort tried to kill Harry because of a prophecy that indicates he will destroy Voldemort.