Mr. Pitt comes back to Queen's Crawley and basically takes over as heir, even though Sir Pitt is still technically alive. He finds the estate tangled up in all sorts of crazy mortgages, lawsuits, and other business dealings and begins to try to make sense of the mess his father has made.
Mr. Horrocks and his daughter aren't arrested but instead buy and run the town's tavern.
Lady Southdown moves to Queen's Crawley with her daughter and son-in-law and proceeds to boss both of them around, and their two kids as well (they have a son and a daughter at this point).
Finally, in a few months old Sir Pitt dies. His son, Mr. Pitt, is now the new Sir Pitt. We will call him young Sir Pitt to avoid confusion.
Young Sir Pitt wants to write a letter to his brother Rawdon telling him about their father's death. He invites him to come and stay at Queen's Crawley.
Jane asks whether they can invite Becky, too.
Young Sir Pitt says of course, but Lady Southdown says absolutely not. Finally the time has come for young Sir Pitt to make his stand.
He tells Lady Southdown to go stuff it and that he will be the only master of the house. She tries to call his bluff by pretending to leave...but he's not bluffing, so she stays.
Young Sir Pitt then dictates a letter to Rawdon and has Jane write it down from his dictation. It's long, complex, beautifully worded, full of quotations, and just generally amazing. Jane is totally floored by how smart her husband apparently is.
Little does she know that he has actually written this letter weeks ago and has been memorizing it all this time just so he can impress her.
Becky is psyched when she gets the letter. Rawdon is sort of grumpy about having to go down to the country, but Becky fills him in on her plans: "I mean that Lady Jane shall present me at Court next year. I mean that your brother shall give you a seat in Parliament, you stupid old creature. I mean that Lord Steyne shall have your vote and his, my dear, old silly man; and that you shall be an Irish Secretary, or a West Indian Governor; or a Treasurer, or a Consul, or some such thing" (40.34).
She plans to go with Rawdon and to leave Rawdon Jr. behind.
The next time Lord Steyne comes over he finds Becky and her companion remaking all the clothes into official mourning clothes. (There was a really complex way to indicate through clothing that you were in mourning.)
Her companion turns out to be...Briggs! She's back! OK, you're right, meh.