Watch The New, New Harry Potter & The Half Blood Prince Trailer J.K Rowling's kid-hero returns for a darker tale in Harry Potter And The Half Blood Prince, the sixth film in the Potter saga. Although Harry Potter is the kind of sci-fi pulp more suited to those with learning difficulties, The Half Blood Prince looks like a hell of a ride. Director David Yates brings you back to Hogwarts where a new professor, Horace Slughorn, begins teaching innocent children how to concoct napalm and 'obsession' potions which will do their adolescent relationships plenty of favours.