As Harry Potter begins his sixth year at Hogwarts, he discovers an old book marked as "the property of the Half-Blood Prince" and begins to learn more about Lord Voldemorts dark past.
During Harry Potters sixth year at Hogwarts, he finds a book that once belonged to the mysterious Half-Blood Prince that earns him the respect of his new Potions professor Horace Slughorn. In addition, Dumbledore must prepare Harry for the ultimate final confrontation by finding out the secret behind Voldemorts power. Meanwhile, a hidden enemy waits in the shadows to carry out a mission given to him by the Dark Lord.
In Harry Potters (Daniel Radcliffes) sixth year at Hogwarts School of Witchcraft, he finds a book marked mysteriously, "This book is the property of the Half Blood Prince", which helps him excel at Potions class and teaches him a few dark and dangerous ones along the way. Meanwhile, Harry is taking private lessons with Dumbledore (Sir Michael Gambon) in order to find out about Voldemorts (Ralph Fiennes) past so they can find out what might be his only weakness.