Chapter 6 - "The Noble and Most Ancient House of Black" - In which Harry, Sirius, and the Weasleys clean the Black house; Kreacher, the Black family house-elf, shows another darker side to house-elves; Harry is shown the Black family tree; and we learn that Sirius is not only related to the Weasleys and Tonks, but to the Malfoys and the Lestranges.
The Mission of the Order of the Phoenix
Thanks to [Sirius] and [Lupin], [Harry] learns that [Voldemort] has been in hiding, rounding up followers, and that the [Ministry of Magic] is terrified of [Dumbledore] and determined not to let anybody believe him. Finally [Molly] stops the conversation, [Lupin] agrees, and everyone heads off to bed.
[Mrs. Weasley] puts [Ron] and [Harry] to bed, where they are soon joined by [Fred] and [George], who [Apparate] in. Together they wonder aloud about the weapon that [Voldemort] is after, and quickly quiet down when they realize Mrs. Weasley is listening outside the door.
Asleep that night, [Harry] dreams that he is in [Care of Magical Creatures] class with [Hagrid], learning about creatures that have cannons for heads.
The morning begins with [Harry], [Hermione], [Sirius], and the [Weasleys] attacking an infestation of [doxies] - and [Fred] and [George] making off with several - and [Molly] runs downstairs to grab lunch for everyone.
With [Mrs. Weasley] downstairs, [Harry] and the [twins] listen in as she berates [Mundungus Fletcher] for trying to stash stolen [cauldrons] in [number twelve, Grimmauld Place].
Ignoring everyone in the room, [Kreacher] arrives, muttering about the filth that has entered his house. He sneaks about the room for a bit, ignoring [Hermione]'s attempts to be friendly, until [Sirius] kicks him out. Hermione then suggests setting him free, but Sirius explains that he can't do so.
The Black Family Heirlooms
As others head to lunch, [Harry] and [Sirius] look over the [Black family tree] on the wall, discussing Sirius's family and his orders to stay in the house that he hates.
The group spends the afternoon cleaning out the [Black family]'s glass cabinets, with [Sirius] doing his best to throw everything away and [Fred] and [George] doing their best to save whatever they can for their joke shop.
As days pass, the cleaning of [number twelve, Grimmauld Place] continues, with [Kreacher] fighting as hard as he can to prevent it. Meanwhile [Harry], despite all the distractions and busyness, can't help but worry about his upcoming hearing at the [Ministry of Magic].