Mrs. Weasley wants them "all to go straight to bed, no talking" (6.2.).
But of course, as soon as the lights are out, they start talking over what they've heard.
Fred and George Apparate (a.k.a. use magic to appear) in Harry and Ron's room.
They start wondering about Voldemort's weapon: "But there can't be anything worse than the Avada Kedavra Curse, can there? [...] What's worse than death?" (6.29).
The next morning, Hermione, Harry, Ron, Fred, George, and Ginny help Sirius and Mrs. Weasley get rid of a Doxy infestation.
Sirius also finds a Boggart in an old writing desk.
Sirius and Mrs. Weasley are both using "carefully light, polite voices" (6.60) because they're feeling sensitive about their big fight the night before.
Kingsley Shacklebot comes to the door to leave a report for Dumbledore.
Fred and George pocket one of the Doxys to experiment on its poison for their "Skiving Snackboxes," which are a "range of sweets to make you ill" (6.79).
The idea is that you would take one of these candies to make you puke, you get to leave class, and then as soon as you're out of class, you can take the rest of the candy to make you feel better.
Fred and George are starting a practical joke shop, and they've been testing this range of candy on themselves.
They are old enough to start their own business, and they have the thousand galleons of start-up money Harry gave them at the end of previous year (see Book Four for details).
They have to keep these plans from Mrs. Weasley, or she will flip out.
Mundungus arrives at the house with a bunch of cauldrons.
Mrs. Weasley starts in on her usual screaming: "WE ARE NOT RUNNING A HIDEOUT FOR STOLEN GOODS!" (6.100).
An elderly house-elf walks into the room where Harry and the rest are cleaning.
It's muttering under its breath: "nasty old blood traitor with her brats messing up my mistress's house, oh, my poor mistress, if she knew, if she knew the scum they've let into her house, what would she say to old Kreacher, oh, the shame of it, Mudbloods and werewolves and traitors and thieves, poor old Kreacher, what can he do ..." (6.108).
Hermione tries to be kind to Kreacher (because better treatment for house-elves is Hermione's big cause), but he just keeps muttering, "... and there's the Mudblood, standing there bold as brass" (6.115).
Hermione whispers, "It doesn't matter [...] he's not in his right mind, he doesn't know what he's —" (6.120).
But Fred answers, "Don't kid yourself, Hermione, he knows exactly what he's saying" (6.121).
Sirius walks in. Sirius absolutely loathes Kreacher, but he can't let Kreacher leave the house, because he knows too much about the order.
So, Sirius and Kreacher are both trapped together in Number Twelve, Grimmauld Place.
Sirius shows Harry a tapestry on the wall. At the top, it says, "The Noble and Most Ancient House of Black. 'Toujours pur'" (6.148).
It's the Black family tree, but Sirius's name has been removed.
Sirius ran away when he was sixteen, because he couldn't stand his Dark magic-using family.
Sirius went to his best friend, James Potter (Harry's father). James's father put Sirius up until he was seventeen and legally old enough to claim his inheritance from his Uncle Alphard.
Sirius's brother, Regulus Black, is still on the family tree.
Regulus was a Death Eater, but he died about fifteen years before.
He tried to leave Voldemort's service, and Voldemort murdered him.
Sirius's cousin Andromeda (Nymphadora Tonks's mother) has also been removed from the family tree. She married a Muggle, Ted Tonks, so the pureblooded Black family disowned her.
Andromeda's two sisters, Narcissa and Bellatrix Black, are still on the family tree. They both married purebloods: Narcissa is now Narcissa Malfoy (mother to Harry's arch-nemesis Draco), and Bellatrix is Bellatrix Lestrange.
Bellatrix Lestrange and her husband Rodolphus are Death Eaters, and they're both in Azakaban.
Harry asks Sirius if he can come back to Number Twelve, Grimmauld Place, if his hearing goes badly and Harry is expelled from Hogwarts.
Sirius doesn't answer directly.
Over the next few days, Mrs. Weasley keeps everyone working hard cleaning up the house.
Several times a day, the doorbell rings and people from the Order show up.
Harry is happy to have something to do at last, but whenever he stops to rest, "the thought of the looming Ministry hearing returned to him" (6.211).
Harry can't stop worrying about what will happen if he gets expelled from Hogwarts.
At last, the night before his hearing comes.
Mrs. Weasley tells Harry that he will go in to the Ministry with Mr. Weasley in the morning.
Sirius wants to come in his dog form, but Dumbledore has left a message saying it's not a good idea for Sirius to leave the house.
Apparently, Dumbledore came by Grimmauld Place the night before.
For Harry, the "thought that Dumbledore had been in the house on the eve of his hearing and not asked to see him made him feel, if it were possible, even worse" (6.224).