Two days later, a letter arrives from Mr. Gardiner: Lydia and Wickham have been found! They are not yet married, but will be, provided that Mr. Bennet pay Wickham a small amount every year.
Wickham is basically ransoming Lydia. If marriage is always partly a financial deal, Wickham has taken it to an extreme.
Mr. Bennet says he strongly suspects that Mr. Gardiner has already paid Wickham much more. Wickham would be a fool to take less for Lydia, he says. The Bennets all agree that Lydia and Wickham must marry, but Jane and Elizabeth wonder how they can ever repay Mr. Gardiner.
Mr. Bennet has no choice. Since Lydia and Wickham are already living together, Lydia's reputation is already tarnished. Marriage to Wickham will salvage enough of it to save the other Bennet girls from the stain.
Jane and Elizabeth share the news with Mrs. Bennet, who is overjoyed, instantly forgetting Lydia's disgrace. Asked about repaying Mr. Gardiner, Mrs. Bennet dismisses the debt, saying that as an uncle he should pay. Mrs. Bennet rushes out to make the news about her daughter's marriage public.
The last part of the novel concerns gratitude, and Mrs. Bennet is despicably ungrateful. With her fake physical ailments, gossipy pride, and willingness to overlook Lydia's recklessness, which almost took down the entire family, Mrs. Bennet is at her shallowest.