Reaching the end of her patience, Umbridge announces that she plans to use the illegal torture curse on him. She is sure that no one will find out, and reveals that it was she and not Voldemort who sent the Dementors to attack him, in an attempt to frame or silence him. As she raises her wand to administer the curse, Hermione pretends to crack and confesses Dumbledore has hidden a powerful weapon in the Forbidden Forest. She leads Harry and Umbridge into the forest where they encounter the centaurs. Umbridge foolishly insults them and an angry centaur carries her off screaming into the woods. However, the centaurs are just as hostile toward Harry and Hermione, but they are saved when Grawp crashes onto the scene and they escape amid the chaos. Running back to the castle, they encounter Ron, and D.A. members Ginny, Neville and Luna, who insist on accompanying them. The students fly to London on the school's Thestrals.
Reaching the room in his dreams, The Hall of Prophecy, Harry sees that Sirius is not there, but notices a glass ball containing some kind of record, that has been labeled with his name. As soon as he takes it down off the shelf, a squad of Death Eaters surrounds them, including many of the recent escapees, and led by Lucius Malfoy. Malfoy reveals that Voldemort planted a false vision to lure Harry to the Ministry, as he is the only one (besides Voldemort himself) who can remove the prophecy from its shelf. The prophecy is what Voldemort has been after the entire year.
Harry and his friends heroically defend themselves, putting up a far tougher fight than the dark wizards expected, but are outmatched. As they are nearly defeated, members of the Order arrive, including Sirius. During the ensuing battle, the glass sphere that Voldemort was seeking is accidentally dropped and shatters, and the record is lost. But just as Dumbledore arrives in person to help, Sirius is blasted with a spell by his Death Eater cousin, Bellatrix Lestrange, and falls backwards through a mysterious veiled archway. Lupin restrains Harry from going after him; Sirius is dead.
The Death Eaters are captured except for Bellatrix, whom Harry pursues into the Ministry’s atrium. Bellatrix is far more powerful, but is taken aback with horror when Harry taunts her that the prophecy has been destroyed, and their mission has failed. In rage, Voldemort appears in person and attacks Harry, but is confronted by Dumbledore. The two duel furiously, but each is unable to finish the other. In an attempt to break the stalemate, Voldemort possesses Harry and tortures him, hoping that Dumbledore will kill Harry to destroy Voldemort. But in the midst of his torture, Harry re-visits his grief for Sirius, and Voldemort is unexpectedly repelled by the emotion. Fudge and the Aurors arrive in time to see the Dark Lord before he Disapparates, taking Bellatrix with him. Fudge finally admits that Voldemort has returned. Rita Skeeter's story is reprinted in the Daily Prophet, exonerating Harry and Dumbledore.