鄧不利多的軍隊
At Hermione's urging, Harry forms a secret student organisation called Dumbledore's Army to teach more meaningful defence against the dark arts as Professor Umbridge is making them read off a textbook. Their plan is thwarted, however, when a Dumbledore's Army member, Marietta Edgecombe, betrays them and informs Umbridge about the D.A., causing Dumbledore to be ousted as Headmaster. Harry suffers another emotional blow, when his beloved godfather, Sirius, is killed during a duel with Sirius' cousin, the Death Eater Bellatrix Lestrange, at the Department of Mysteries, but Harry ultimately defeats Voldemort's plan to steal an important prophecy. Rowling stated: "And now he [Harry] will rise from the ashes strengthened." A side plot of "Order of the Phoenix" involves Harry's romance with Cho Chang, but the relationship quickly unravels. Says Rowling: "They were never going to be happy, it was better that it ended early!"