Thanks to the testimony of Mrs. Figg, Harry can prove his innocence with the aid of Professor Dumbledore. Nevertheless, Harry is angry that Dumbledore seems to be ignoring him.
The hearing was a scheme to kick Harry out of school. The Minister for Magic, Fudge, wants to discredit Harry and Dumbledore. He refuses to accept that Voldemort has come back and starts interfering in Hogwarts,
Fudge sends Dolores Umbridge, to Hogwarts as Defense Against the Dark Arts instructor and to pull strings in his favor.
She is spying on Harry and Dumbledore, whom Fudge assumes is trying to steal his post.
Professor Umbridge is an ambitious bureaucrat monster who tightens controls on every aspect of Hogwarts, especially Harry.
She forbids students gatherings and appoints the worst bullies, including Draco Malfoy, to an Inquisitorial Squad.
Breaking the rules, Hermione conceives Dumbledore's Army, a group to learn magical defense taught by Harry Potter.
Upon all bad things, Harry's been still having terrible nightmares in which he seems to be looking through the eyes of Voldemort.
Harry sees Voldemort's serpent attacking Mr. Weasley in the basement of the Department of Mysteries and informs Dumbledore.
Professor Dumbledore tells Harry to start studying Occlumency to protect his mind from scannings. The teacher is Professor Snape of course – Harry's most hated teacher.
One day, Harry sees Professor Snape's worst memory and starts to doubt all his heroes and idols.
Umbridge and Fudge find out about the D.A. meetings and try to arrest Professor Dumbledore, who flees from Hogwarts.
In another nightmare, Harry sees Voldemort torturing Sirius.
Umbridge attempts to stop them and finish with Harry, but Hermione lures her into the Black Forest where the centaurs end up helping them.