Harry Potter and the Order of the Phoenix first introduced audiences to the ‘Lost Prophecy’, which ultimately became the most important part of the franchise. During the fateful Battle of the Department of Mysteries, the Death Eaters are attempting to obtain the Prophecy to deliver to their master, Lord Voldemort. In Order of the Phoenix’s book, Harry questions the Death Eaters about the Prophecy’s importance, to which Lucius Malfoy responds with “Haven’t you ever wondered why the Dark Lord tried to kill you as a baby?”. It is here when Harry first realizes the Prophecy’s value.