At dinner that night, Harry angrily listens to everyone talking about him. Nobody tries to pretend they're not. He grumbles that everyone seemed to believe Dumbledore last summer, but Hermione says that she's not sure anyone actually believed Dumbledore. As Harry snaps again, Hermione says that students had all summer to read the Prophet and decide that Dumbledore's crazy. They collect their bags to start on homework and Hermione furiously cries that Dumbledore can't possibly expect Umbridge to teach them in their O.W.L. year. Ron reminds Hermione that Umbridge also wants students to spy for her, and they start their Potions essay.
Because Harry is so wrapped up in his own experience and is so angry, he doesn't have the wherewithal to consider that Hermione is likely correct in her assessment. The Prophet did a fantastic job of discrediting Harry by preying on the fact that, judging by events in previous novels, the wider Wizarding population is relatively easy to manipulate through the press.
Hermione gets distracted by Fred, George, Lee Jordan, and a group of fainting first years. Hermione marches over and insists that the twins can't test on students. She threatens to write to Mrs. Weasley if they continue and then announces she's going to bed. She sets out some woolly objects and covers them in trash and explains to Ron that they're hats for house-elves to pick up while they’re cleaning. Ron is aghast that Hermione would try to trick the elves into freedom. As soon as Hermione is gone, he removes the trash so the elves can at least see that they’re hats.
Readers will recall that house-elves become free when their master gives them clothes, but most elves don’t seem to want to be free, so Hermione is essentially trying to trick them because she assumes that she knows what’s best for them. She still hasn’t learned that to be a good ally, she needs to meet those she wants to help where they are and help them achieve goals that they want to meet. Though Ron is normally callous and uninterested in helping house-elves, the fact that he sees this attempt as the trick it is reminds the reader that anyone can do the right thing and advocate for others.
The next morning, both Flitwick and McGonagall also start their classes by talking about O.W.L.s. McGonagall insists that even Neville can do well in Transfiguration if he studies and builds up confidence. Harry and Ron spend their lunch researching their Potions essay and then join Hermione outside for Care of Magical Creatures with the Slytherins. Professor Grubbly-Plank introduces the class to bowtruckles, stick-like creatures that guard trees. She assigns a drawing as classwork, and as Harry moves to pick a bowtruckle, he tries to ask Grubbly-Plank about Hagrid. She refuses to answer, and Malfoy smirks that Hagrid might be injured by something "too large" for him. Harry wonders what Malfoy knows.
The fact that every teacher is bringing up O.W.L.s drives home the importance of these tests as a requirement to entering into the adult Wizarding world. This makes it so Harry, Ron, and Hermione begin to grasp the gravity of the tests and understand just how close they are to becoming adults in the world. McGonagall's comment to Neville about being able to pass Transfiguration reminds the reader that Neville isn't unintelligent; he's just unsupported in his studies and as a person and therefore lacks confidence.
Hermione assures Harry that Dumbledore would've said something if Hagrid was in trouble. Malfoy makes more mean comments about Hagrid and Harry follows Ron and Hermione to Herbology in a horrible temper. At the greenhouses, Luna approaches Harry and tells him that she believes that Voldemort is back. When Parvati and Lavender laugh at Luna's eccentric jewelry, Luna angrily says that people used to believe that the “Blibbering Humdinger” and the “Crumple-Horned Snorkack” weren't real either. Hermione reminds Luna that those creatures aren't real, which annoys Harry, since Luna could also see the winged horses. Ernie MacMillan also approaches Harry to voice his support.
Hermione is able to trust Dumbledore so completely here because she's had more communication with Dumbledore this year than Harry has, given that she saw him over the summer. She’s also generally better at taking the long view than the more impulsive Harry, who feels as though he has little reason to trust Dumbledore, since Dumbledore hasn't been around to help him interpret the scary things that have been happening to him. As Harry feels more cut off from adults he trusts, he in turn stops asking for help and tries to go it alone.
Before dinner, Angelina storms up to Harry and reprimands him for getting detention on Friday night when he's supposed to be at Keeper tryouts. Harry glumly eats some dinner and hopes that Umbridge won't keep him too long. He heads for Umbridge's office and is horrified to see that it's covered in lace, flowers, and ornamental plates with kittens on them. Harry sits down and asks Umbridge if he can move his Friday night detention, but she smiles and says that this is his punishment for telling lies. She says that Harry is going to write lines with her special quill. She tells him to write "I must not tell lies" until the message "sinks in." She says that Harry doesn't need ink to write with this quill.
Umbridge's detention further compounds the trauma Harry experienced at the end of the last novel, both by causing even more physical pain and by showing Harry that he'll be punished for telling the truth about what happened. As a villain, Umbridge is a prime example of the fact that evil doesn't have to look a certain way—her exaggerated femininity shows Harry that he can't underestimate anyone, as evil can come in many forms.
When Harry writes his first line, he gasps and sees that the words also etch themselves into the back of his hand and then heal over. He writes until after midnight. Umbridge inspects his red and sore hand and sends him away. Harry spends the next morning doing homework with Ron, who won't tell Harry why he didn't do his homework last night. Harry tells Ron that he did lines for Umbridge, but doesn't tell him about the special quill. The rest of Harry's day is awful, since he didn't do his homework and he feels as though he can't tell Ron and Hermione about Umbridge's punishment.
Again, because Harry feels so alone in the world, he's not comfortable reaching out for help or in this case, even asking for comfort or validation that what's happening to him is horrendous. While it's unclear what Harry's reason is for keeping the particulars of his detention a secret, it nonetheless illustrates how Harry's sense of being alone causes him to isolate himself even further.
That night, Harry again writes lines until midnight. He does homework in the common room for hours after he gets back and the next night, "I must not tell lies" remains etched in the back of his hand, dripping blood. Umbridge lets him go at 7 pm. Harry wonders if he hates Umbridge more than Snape as he runs into Ron, hiding with his broomstick. Ron admits that he's been practicing to try out for Keeper. Then he catches sight of Harry's hand. He looks sick as Harry explains what Umbridge's lines really entail. Harry refuses to tell McGonagall or Dumbledore.
It's telling that when encouraged to ask an adult for help—even one like McGonagall, who isn't ignoring Harry—Harry still refuses. This shows that as Harry continues to feel more isolated and alone, he also begins to distrust even the most reliable and trustworthy adults who might be able to help him. Ron's sympathy, on the other hand, shows Harry that his sense that what's happening is wrong isn't out of line.
On Friday evening, Harry tries to shift his chair so he can see the Quidditch pitch from Umbridge's window. After dark, Umbridge approaches him to check his hand and as she touches him, Harry's scar throbs and he feels something strange in his stomach. He leaps away and Umbridge dismisses him. In the common room, Ron shouts that he got the position of Keeper. Harry approaches Hermione, who's asleep by the fire. She jerks awake and listens to what happened to Harry in Umbridge's office. Hermione wonders if it has nothing to do with Umbridge and suggests he speak to Dumbledore. Harry snaps that Dumbledore only cares about his scar. Hermione reminds him that he can't write to Sirius about it and heads to bed.
Here again, Hermione has no reason to not trust adults like Dumbledore or McGonagall, so her advice to go to Dumbledore makes perfect sense and reflects her sense of security with the adults in charge. However, it's also worth keeping in mind that because Hermione feels so secure, she's able to think more critically about what's going on with Harry—and Harry will later discover that she's right. This then shows how, because Harry is so afraid and angry about things, he ignores possible truths coming from even the people he does trust.