Harry Potter and the Half-Blood Prince Horace Slughorn Pensieve Horcruxes Draco Malfoy Dark Arts Defence Against the Dark Arts Death Eater Harry Potter
In the sixth book, Harry Potter and the Half-Blood Prince, Snape teaches Defence Against the Dark Arts while Horace Slughorn becomes the Potions master. Harry finds an old textbook with annotations by the Half-Blood Prince, due to which he achieves success in Potions class. Harry also takes lessons with Dumbledore, viewing memories about the early life of Voldemort in a device called a Pensieve. Harry learns from a drunken Slughorn that he used to teach Tom Riddle, and that Voldemort divided his soul into pieces, creating a series of Horcruxes. Harry and Dumbledore travel to a distant lake to destroy a Horcrux; they succeed, but Dumbledore weakens. On their return, they find Draco Malfoy and Death Eaters attacking the school. The book ends with the killing of Dumbledore by Professor Snape, the titular Half-Blood Prince.
