Harry's back at Hogwarts, but he's still dealing with evil entities trying to kill him. Sirius Black (Oldman), a rogue wizard and convicted murderer has escaped from Azkaban Prison. Harry also has to deal with the onset of puberty and the trials of being a teenager. Michael Gambon takes over the role of Dumbledore from the late Richard Harris. Cuaron is more faithful to the spirit of the books, driven more by emotion and feeling, and less by the marketing department. Cuaron was author J.K. Rowling's choice to direct the franchise from the start.