"For me, the Harry Potter films have always been about a loss of innocence," says Daniel Radcliffe, the actor behind the title character, who can perhaps no longer be called the boy wizard. "When Harry came into this world, it was all just amazing and brilliant and kind of pure. But as the films have gone on, that's totally disintegrated, and he's realizing that the wizarding world has just as many, if not more, challenges than the world he grew up in before."

"In the last film, we were watching Harry at a difficult stage—tormented by dreams, questioning himself and beset by personal demons. Now he's a year older and that brings a different set of issues and responsibilities."

"The book says it is the ‘Property of the Half-Blood Prince,' but there is no name and no other record of him, so his identity is an enigma. But whoever he was, he was obviously very smart; he was capable of taking the conventional recipes for certain potions and spells and making them significantly better. He was an original thinker but also quite a dark thinker. The things he came up with eventually lead Harry into some very intense territory."