Hermione goes back to Hagrid's the next morning while Harry and Ron do homework. She returns before lunch and says that he's insistent that he wants to teach them interesting things. On Monday morning, everyone is thrilled to have Hagrid back, though Harry also recognizes that Grubbly-Plank's lessons were safer and better than Hagrid's usually are.
Hagrid is one of Harry’s closest friends, but he can also recognize that Hagrid isn’t necessarily the best teacher, especially given his love of creatures that others might consider dangerous.
Hagrid greets his class at the edge of the forest, carrying half of a cow carcass, and then leads them into the trees. He snaps at Malfoy when Malfoy suggests that whatever creatures they're looking for aren't safe. He then throws the cow carcass on the ground and makes a shrieking cry. A few minutes later, one of the ghostly winged horses enters the clearing and begins to tear at the cow. Harry is relieved that he's not crazy, but Ron asks why Hagrid doesn't call for the animals again. Most students look just as confused. Only Harry, Neville, and one other student can see the creatures. The others gasp when Hagrid points to the carcass, which to them, looks like it's vanishing. He says the creatures are called thestrals.
Here, Hagrid is able to validate Harry's lived experience in an extremely meaningful way by giving him proof that he's not crazy. This in turn allows Harry to gain more confidence in his own story and experience, and in the future, will help him be able to believe his own intuition.
Parvati insists that thestrals are unlucky, but Hagrid says they're useful and clever. Hermione raises her hand and says that the only people who can see thestrals are those who have seen someone die. As Hagrid starts to talk about the animals, Harry hears Umbridge's "hem, hem." Hagrid greets her brightly, but Umbridge acts as though she can barely understand him. As she makes notes, she narrates that Hagrid uses "crude sign language" and has a poor memory, which flusters Hagrid. Hagrid introduces one thestral, and when Umbridge notes that the Ministry believes thestrals are dangerous, Hagrid chuckles. Umbridge writes that Hagrid takes pleasure in violence and danger.
Notice that at this point, Harry expresses little curiosity as to whom Neville saw die. This shows that Harry is still caught up in his own life and his own problems. Umbridge's act of treating Hagrid as though he's unintelligent and not fluent in English is a way for her to show him that she doesn't think he belongs—and to use her own prejudices, and those of others, to remove him from his relative position of power as a teacher. Hagrid doesn’t know that Umbridge is fundamentally biased against him, so he doesn’t try to defend himself and falls for her cruel traps.
Umbridge announces and mimes that she's going to speak to students about Hagrid while Hagrid teaches. Pansy Parkinson tells Umbridge loudly that Hagrid's speech sounds like grunting, while Umbridge leads Neville to say that he's afraid of Hagrid. Pleased, Umbridge slowly and loudly tells Hagrid when he'll receive his inspection results and leaves. Hermione is beside herself and believes that Umbridge is going after Hagrid because he’s half-giant. She says the thestral lesson was surprisingly good for Hagrid and says she wishes she could see the thestrals. She then takes this back when she realizes what she implied—that she wishes she had seen someone die.
Umbridge again shows her blatant racism, treating Hagrid like an animal to denigrate and embarrass him in front of his own students. While Hermione's comment about wanting to see the thestrals may not have been in good taste, she does have genuine curiosity about them.
In December, Ron complains about having to supervise decorating the castle and Hermione laments that she hasn't had time to knit elf hats. Harry doesn't tell her that Dobby is taking all of them. He thinks that for the first time ever, he wants to spend Christmas away from Hogwarts. Harry’s spirits lift when Ron tells him that he's coming to the Burrow, the Weasleys’ home, with him. Harry still feels guilty that Sirius will spend Christmas alone.
Harry cares about many people, but doesn’t know how support himself, the Weasleys, and Sirius at the same time.
When Harry arrives at the Room of Requirement for the final D.A. meeting before the holiday, he discovers that Dobby decorated the room with pictures of Harry's face. Luna arrives just as Harry takes the last ones down. Angelina arrives a minute later and tells Harry that Ginny is Gryffindor’s new Seeker. When everyone is there, Harry announces that they'll review everything they've learned. With pride, Harry notes how much everyone has improved and says that after the break, they can start on more advanced magic.
It's important that Harry recognizes how essential it is that the D.A. members learn the basics before they move onto advanced things. This shows that he's taking what he learned from the Order to heart: that basic maintenance and knowledge acquisition are even more important than showy displays of heroism.
After everyone clears out, Harry and Cho are the last two in the room. Harry turns around to see her crying, and she says that she wonders if Cedric knew all of these spells. Harry assures her that Cedric did, but Voldemort killed him anyway. Feeling miserable, Harry notices that Cho still looks pretty. Then she comments on the mistletoe, tells Harry she likes him, and kisses him. Harry makes it to the Gryffindor common room a half hour later. He's in such a state of shock that he can't tell Hermione and Ron what happened. When Harry confirms that they kissed, Ron laughs and Harry starts to smile.
Though Harry is young and rather oblivious to others’ emotions—and so would likely find Cho's emotions confusing anyway—it's possible that her behavior around him is even more inscrutable because of Harry's own precarious emotional state at this point. This is especially the case because they share trauma surrounding Cedric Diggory’s death, but in entirely different contexts. Harry actually saw Cedric killed, while Cho was dating him at the time.
Harry notes that Cho was crying and wonders if he's bad at kissing, but without looking up from her letter Hermione says that Cho spends most of her time crying lately. When Ron and Harry look confused, Hermione explains that Cho likely feels sad that Cedric died, guilty about liking Harry, is worried about rumors, and fears being kicked off the Quidditch team. Ron insists it's impossible to feel so much at once and Hermione glares at him. She asks Harry if he's going to ask Cho out, which makes Harry nervous.
Harry and Ron's confusion about what Cho is feeling reminds the reader that being able to interpret and appropriately respond to another person's emotions is a learned skill, not knowledge that everyone is born with. This reinforces that the boys are still in the early stages of coming of age emotionally and romantically--hopefully, they'll improve and become more empathetic as they grow. It also shows how emotionally intelligent Hermione is at this point, especially in comparison to her two male best friends.
When Ron asks, Hermione admits she's writing to Viktor Krum. They all sit for another twenty minutes before Hermione excuses herself. Ron grumpily wonders what Hermione sees in Krum, and Harry decides to ask Cho out when he sees her again. Harry falls asleep and dreams he's back in the D.A. room, arguing with Cho, but then the dream changes and Harry is a snake gliding along a stone floor. He sees a man sleeping at the end of a corridor. When the man notices Harry, Harry bites the man until he falls to the ground in a pool of blood.
By talking to each other about Krum and romance, Harry and Ron attempt to grow and learn together. This dramatic dream marks a major change in Harry’s ability to seemingly share Voldemort’s emotions, but it remains to be seen if the adults he trusts will believe him about the dream or dismiss him, as they have previously.
Harry wakes up, sweaty and with his scar burning. Ron looks frightened, and Harry tells Ron that Mr. Weasley—who was the man—has been attacked. Neville runs for help. Harry vomits and insists that what he saw was real. McGonagall arrives and Harry tells her that a snake attacked Mr. Weasley. She looks at him with horror, and when Harry insists he isn't lying or crazy, McGonagall says she believes him and takes him to Dumbledore.
Harry's reaction upon waking suggests that committing violence, even in a dream, can be just as traumatizing as being the victim of violence. McGonagall telling Harry that she believes him is probably the best thing she can do for him in this situation, as it encourages Harry to take this seriously and believe himself.