Cast members from all "Harry Potter" films reunite in a retrospective special to celebrate the anniversary of the first film, including interviews and cast conversations.

Harry, Ron and Hermione walk away from their last year at Hogwarts to find and destroy the remaining Horcruxes, putting an end to Voldemort's bid for immortality. But with Harry's beloved Dumbledore dead and Voldemort's unscrupulous Death Eaters on the loose, the world is more dangerous than ever.

As Harry begins his sixth year at Hogwarts, he discovers an old book marked as 'Property of the Half-Blood Prince', and begins to learn more about Lord Voldemort's dark past.

Harry starts his fourth year at Hogwarts, competes in the treacherous Triwizard Tournament and faces the evil Lord Voldemort. Ron and Hermione help Harry manage the pressure – but Voldemort lurks, awaiting his chance to destroy Harry and all that he stands for.

Ignoring threats to his life, Harry returns to Hogwarts to investigate – aided by Ron and Hermione – a mysterious series of attacks.