Harry leaves the Great Hall to find McGonagall. Madam Pomfrey tells Harry that McGonagall has been taken to St. Mungo’s. Realizing that he has no one else to turn to, Harry runs to find Ron and Hermione. Hermione warns Harry that Voldemort may be attempting to lure Harry to the Department of Mysteries, knowing that Harry would do anything to save Sirius.
Harry doesn’t want to take any chances and insists they get to the Ministry as soon as possible. Ginny and Luna walk in and offer their help. Hermione convinces Harry to use the fire in Umbridge’s office to first see if Sirius is actually at number twelve. Ginny and Luna agree to stand guard in the hallway, and Ron creates a distraction. Inside Umbridge’s office, Harry uses Floo powder to transport himself to number twelve. Kreacher appears and tells Harry that Sirius is at the Department of Mysteries. Harry is pulled from the fire by Umbridge, who demands to know to whom he was speaking. Harry sees that Ginny, Hermione, Ron, Luna, and Neville have been captured by Umbridge’s Squad. Snape enters Umbridge’s office, and Harry yells “He’s got Padfoot at the place where it’s hidden!” in hopes that Snape will contact someone in the Order.
Umbridge admits she was the one who sent the dementors to Little Whinging last summer. Before she can use an illegal Cruciatus Curse on Harry, Hermione screams and tells Umbridge that Harry was trying to contact Dumbledore. When Umbridge asks why, Hermione tells her that Dumbledore has asked the students to build a weapon for him and that they needed to let him know the weapon was ready. Umbridge seems to believe her and demands that she and Harry lead her to the weapon.
Harry follows Hermione out of Hogwarts, with Umbridge in tow. Harry has no idea where Hermione is taking them. They enter the Forbidden Forest but do not take the path toward Grawp. Moments later, a herd of Centaurs surrounds them. Umbridge insults the Centaurs, and they carry her away. Grawp appears and recognizes Hermione. In broken English, he demands to know where Hagrid is. Hermione screams that she doesn’t know, and, in the chaos, she and Harry run to safety. On their way out of the forest, they run into Ron, Ginny, Neville, and Luna, who escaped their captors using Defense skills and left to find Harry and Hermione in the forest. Harry wants to go to the Ministry alone, but his friends insist on helping Harry save Sirius. Luna spots a herd of thestrals, who can take them to the Ministry.
Harry, Ron, Hermione, Luna, Neville, and Ginny ride thestrals to the Ministry, where they take the elevators to the Department of Mysteries. Harry recognizes the corridor from his dreams and knows exactly which door to enter. There are more doors in the next chamber, and Harry doesn’t know which one to use. They try several. One room houses a tank full of brains, and the next has an ancient archway with tattered black curtains. Harry hears whispering behind the curtains. Finally, they find the right door and move toward the dusty spheres, realizing that Sirius is not there. Harry begins to think Hermione’s suspicions were correct. Ron notices that one of the dusty spheres has Harry’s name on it, as well as Voldemort’s. Harry picks it up. Moments later, he hears Lucius Malfoy order him to hand it over.
With Dumbledore replaced, Hagrid missing, and McGonagall hospitalized, Harry is left without a single ally from the Order, save Snape, at Hogwarts. Even though Harry doesn’t trust Snape and doesn’t know whether or not Snape will understand his heavily veiled message, Snape is, ultimately, Harry’s last shot at contacting the Order for help. With no authority figures left to run to, Harry once again turns to his friends, who prove to be invaluable. Ron, Ginny, Luna, and Neville all help to ensure Harry and Hermione’s safe entrance into Umbridge’s office. Then Hermione thinks of a way to free them from Umbridge’s custody before Umbridge can curse Harry. After they’ve all escaped relatively unharmed, Harry tries to discourage his friends from joining him at the Ministry, but they insist, once again, on helping. In the absence of adult allies, Harry’s peers step in and prove to be fully competent supporters.
Umbridge treats the Centaurs poorly, insulting their intelligence and traditions, but the Centaurs refuse to accept this kind of treatment and challenge Umbridge’s rash demands—something the bullied Hogwarts students are unable to do. The Centaurs, unlike the students, aren’t cowed into submission by the power of Umbridge’s credentials. Since the Centaurs operate by their own rules and don’t respond to any lone governing body, such as the Ministry of Magic, Umbridge’s credentials and titles are meaningless to them. Instead, the Centaurs have established their own system of justice, which seems to change depending on the circumstances. When Harry and Hermione were in the woods with Hagrid, for example, the Centaurs left them alone, deeming them “innocents.” Now, even though only a few weeks have passed, they find Harry and Hermione suddenly too old to be shielded by childhood. The Centaurs’ rules are pliable, but cruelty generally begets cruelty, and Umbridge is finally, rightfully punished for her arrogance and presumptiveness. Umbridge has brought so much unhappiness over so many months, but it takes the Centaurs only a few moments to dispense with her.
Harry’s desperation to be successful in his search for Sirius leads him to make several foolish errors and reveals the depth of Harry’s devotion. Harry never fully considers Hermione’s warning that Voldemort may be luring Harry into a trap, and he doesn’t stop to figure out why it’s so urgent for him to learn Occlumency. Having been through dangerous adventures before, Harry should, at the very least, suspect Occlumency is important for a reason and that this whole rescue of Sirius might be a hoax or a trap. Despite Harry’s past experiences, he allows himself to be driven not by logic but by fear. He believes Sirius is in grave, immediate danger, and this fear overshadows rational thought. Though Harry’s friends may realize they should stop and consider possibilities, they, too, are propelled forward by Harry’s urgency.