For the third film in the Potter series, Mexican-born director Alfonso Cuarón takes the helm. An unconventional choice, he had not seen the first two films or read the books, but producer David Heyman and creator J.K. Rowling thought he would bring a fresh perspective to the series, which he does. Now in his third year at Hogwarts, Harry discovers that convicted murderer Sirius Black (Gary Oldman), who killed Harry’s parents, has escaped from the fortress of Azkaban and now has their son in his criminal sights. Cuarón brings a darker atmosphere and look to the series, which, in this episode, reflects many transitions: The young wizards are undergoing puberty, a new Dumbledore (Michael Gambon) has arrived, and iconic composer John Williams supplies his last original score for Potter world. Ave atque vale.