Chapter 30 - "Grawp" - In which Harry recalls the dream again, the Gryffindors play Ravenclaw for the final match of the Quidditch season, and Hagrid introduces Harry and Hermione to his half-brother, Grawp, making them promise to look after Grawp if he has to leave. Gryffindor wins the match and the Quidditch Cup, and Ron is carried triumphantly off the pitch.
Harry Desires to Speak to Sirius
[Hermione] spends [Defence Against the Dark Arts] trying one final time to dissuade [Harry] from breaking into [Umbridge's office], but as class ends and Umbridge goes running off toward the distraction, Harry makes up his mind and heads off to do it anyway.
With his nerves almost at a standstill, [Harry] breaks into [Umbridge's office] and uses the [Floo] to talk to [Sirius] and, as it turns out, [Lupin]. He asks about [James] and they discuss [Snape]'s memory for a bit, along with the fact that Snape is no longer teaching Harry [Occlumency], until finally Harry hears footsteps and has to go.
Fred and George Bid Farewell
[Harry] hides under his [Invisibility Cloak] as [Filch] rushes in to get an "Approval for Whipping," presumably for [Fred and George]. Once he rushes back out, Harry slips out of the office as well, and heads toward the noise in the [entrance hall].
In the [entrance hall], [Harry] finds [Umbridge] confronting the [twins] for creating a swamp in a school corridor. Just as she and the [Inquisitorial Squad] rush in to capture them though, the twins [Summon] their [brooms], kick off into the air, give a quick plug to their joke shop and a quick good-bye to [Peeves], and zoom off triumphantly into the sunset.
With [Fred and George] gone, their departure from [Hogwarts] quickly becomes legendary. [Umbridge] is unable to remove their [swamp] so it remains behind, and students quickly get out of control, using [Skiving Snackboxes] to skip classes and jinxing members of the [Inquisitorial Squad]. Meanwhile [Peeves] causes even more mayhem, aided and abetted by the staff.
In [Charms] class, [Hermione] wonders whether she should admit her knowledge about [Montague]'s disappearance and subsequent confusion, [Ron] worries about his mom's reaction to [Fred and George]'s leaving [Hogwarts], and [Harry] admits that he gave the twins the seed money to start their new [joke shop].
[Hermione] once again questions [Harry] on his [Occlumency] lessons, leaving him feeling guilty, but nevertheless wanting to continue his dreams and find out what's behind the door of the [Department of Mysteries].
The Quidditch Final and Grawp
The final [Quidditch] match of the season approaches, with [Ron] seeming more confident than ever, and [Luna] sporting a dramatic eagle hat.
The [Gryffindor]-[Ravenclaw] [Quidditch] match begins, to determine the winner of the [Quidditch Cup]. Partway through, though, [Hagrid] interrupts [Harry] and [Hermione], asking them to follow him away from the game.