Moody silences Harry when Harry tries to ask what the Order of the Phoenix is. When Lupin tells Harry to think about what he just read, a house suddenly seems to inflate out of thin air, wedged between two others. Lupin taps the door with his wand and it creaks open. Quietly, Harry and the others step inside. Moody lifts the Disillusionment Charm and Harry feels unsettled by the gloomy and dirty entryway. Mrs. Weasley emerges, hugs Harry, and sends Harry upstairs to find Ron and Hermione until the “meeting” is over. She tells him to be quiet so that he doesn't "wake anything up," and leads him up the stairs.
The way that Mrs. Weasley speaks about the house implies that there's something funny about it, and it could be dangerous. Again, when nobody will answer Harry's questions and especially when they send him away from the meeting, they tell Harry through these actions that he's too young to participate or know too much, and his job is to not provoke the house. In all this is a disorienting experience, and nothing like he was expecting.
When Harry opens the door, Hermione throws herself at him hugs him, apologizing for her "useless" letters. She says that Dumbledore made them promise not to say anything. Hedwig swoops down onto Harry's shoulder, and Ron and Hermione show Harry their pecked hands, as Hedwig had obeyed Harry’s order to make sure his friends wrote long replies. Growing suddenly moody, Harry doesn't feel sorry about their injuries. As they talk more, he realizes that his friends knew that people were following him, and tries to stay calm. He asks why Dumbledore didn't tell him anything, and as Ron and Hermione try to explain, Harry starts shouting angrily about his awful summer and his feelings of being neglected while Ron and Hermione got to be in the middle of the action.
Notice that while Harry is perfectly justified in being angry with Ron and Hermione, he's also upset because he believes that they're getting to do exciting things by living at the headquarters of the resistance movement. Harry will soon learn that this couldn't be further from the truth; as young people who can't join the resistance, living here is rather gloomy and boring. Harry's conceptualization of the resistance as constantly exciting illustrates his youth and his preconceptions about what war is really like.
Harry finally takes a breath and asks what the Order of the Phoenix is. Hastily, Hermione and Ron say that it's the resistance group. She says that thanks to Fred and George's newly invented Extendable Ears, they know that some members are recruiting people, keeping tabs on Death Eaters, and guarding Harry. They explain too that they've been decontaminating the house. Suddenly, Fred and George Apparate into the bedroom and tease Harry about shouting. They note that his shouts are making it difficult to use their Extendable Ears and are crestfallen when Ginny enters and says that they can't use the Ears anyway: Mrs. Weasley put an Imperturbable Charm on the door. Fred and George sigh that they wanted to hear what Snape's been up to.
Everything that Ron and Hermione tell Harry about the Order of the Phoenix and, specifically, what they've been doing suggests that almost nothing the Order does right is especially exciting. Notice, however, that what's exciting is acquiring information (in this case, about what Snape's doing). Though all the children dedicate themselves to finding out as much as possible and view acquiring information as an important task, note how Harry thinks of information acquisition at this point—it never occurs to him that the adult members of the Order are doing the exact same thing in their work.
Fred, George, and Ginny explain that Bill now has a desk job in London so he can work for the Order and give private English lessons to Fleur Delacour, and Charlie is still in Romania trying to bring foreign wizards into the Order. Harry asks about Percy, and all the Weasleys' faces become dark and angry. They explain that Percy was promoted to a position in Fudge's office a week after term ended last year. Mr. Weasley knew that Fudge likely promoted Percy so he could spy on the Weasleys, who are close to Dumbledore and therefore are Fudge's enemies. After this accusation, Percy declared his loyalty to the Ministry, disowned his family, and moved to London.
Along with Vernon and Petunia, Percy shows here that blood relationships aren't a guarantee that someone will behave loyally to their family members. Percy also illustrates the novel's later assertion that the world isn't split up into people who are entirely good or entirely evil. Though Percy isn't a bad guy, he's still making choices that align him with people making even worse decisions—which in turn, leaves him vulnerable to manipulation by Voldemort.
Harry says that Percy has to be aware that Voldemort is back, but Ron explains that Percy doesn't think Harry is trustworthy and he believes the Daily Prophet. Harry has no idea what this means, but Hermione explains that if he were to read the paper cover to cover, he'd see that the Prophet slips Harry in as a standing joke every time they print something that sounds far-fetched. They are trying to discredit him and thus maintain that he is lying about having seen Voldemort return. Harry is furious.
The way that Fudge and the Daily Prophet are going about discrediting Harry also makes his experience of trauma worse. Refusing to admit that Voldemort is back means that Harry has to deal with the compounded trauma of constantly defending his lived experience (which itself haunts him) to very powerful people.
The children hear steps on the stairs, so Fred and George Apparate away. Mrs. Weasley calls everyone for dinner. Ron and Hermione apologize to Harry for not telling him more. Then, Hermione and Ron tell Harry about Kreacher, the house-elf who lives at Grimmauld Place and who is, according to Ron, crazy. The trio stops when they see a crowd in the hallway, including Snape. Fred and George try to lower an Extendable Ear, but the group moves away. After Tonks and Lupin lock the door behind everyone, Tonks knocks over an umbrella stand and velvet curtains fly open to reveal a painting of a woman. The woman screams about "half-breeds, mutants, and freaks" and the other portraits join in. Sirius Black appears, and he and Lupin close the curtains. Sirius explains that the portrait is of his mother, Mrs. Black.
Mrs. Black’s portrait is presumably what Mrs. Weasley didn't want Harry to wake up, and the content of her screams and shrieks suggest that the house itself isn't supportive of the aims of the Order of the Phoenix—Mrs. Black seems to want a pure-blooded, entirely human world. The fact that this sentiment seems to be part of the house speaks to how insidiously these beliefs in wizard superiority and a fear of difference can be ingrained in people--in this case, it's part of the architecture, just as racist or discriminatory legislation can make the architecture of a society racist.