Elizabeth is stunned. At first, she doesn't believe any of this information because she thinks that Darcy's tone in the letter seems unrepentant and haughty. But, upon rereading the letter, she starts to see things in a different light. Elizabeth realizes Wickham was inconsistent and that his history was never verified. She realizes that Wickham tricked her.
At first, Elizabeth misreads the letter just as she has misread Darcy. But then she realizes that her prejudice caused her to misread Wickham without challenging his flimsy story or motives, as she always had done with Darcy.
Elizabeth is utterly ashamed. She had considered herself to be a discerning judge of character, but now she sees that she was blind and prejudiced. Until this moment, she thinks, she never really knew herself.
Elizabeth realizes her errors and faults, and begins to rebuild her character. She doesn't realize it yet, but Darcy is undergoing a similar process.
Elizabeth also rereads the part of the letter about Jane, and realizes that she can't blame Darcy for intervening: Jane was reserved, as Charlotte had pointed out; and she must admit that the other Bennets were terribly crass.
Everything looks different when prejudices are removed. But at least Elizabeth has the strength to face and accept her failures.
On returning to the parsonage house, Elizabeth learns that Darcy and Colonel Fitzwilliam had both visited to say good-bye.
Elizabeth thinks she'll never see Darcy again because she had so wrongly insulted him.