Main article: Harry Potter and the Half-Blood Prince (film)

In Harry's sixth year at Hogwarts, Lord Voldemort and his Death Eaters are increasing their terror upon the Wizarding and Muggle worlds. Headmaster Albus Dumbledore persuades his old friend Horace Slughorn to return to Hogwarts as a professor as there is a vacancy to fill. There is a more important reason, however, for Slughorn's return. While in a Potions lesson, Harry takes possession of a strangely annotated school textbook, inscribed 'This is the property of the Half-Blood Prince'. Draco Malfoy struggles to carry out a deed presented to him by Voldemort. Meanwhile, Dumbledore and Harry secretly work together to discover the method on how to destroy the Dark Lord once and for all.