She finds this an odd coincidence, especially since she had told him it was a favorite spot of hers, specifically so he'd avoid it.
Darcy makes some comments that make her believe he is alluding to Fitzwilliam, and she wonders if Fitzwilliam is interested in her.
Elizabeth winces when Fitzwilliam comes to Charlotte's house one day and catches her alone.
Their discussion meanders from marriage to Miss Darcy. Elizabeth comments that, if she is like her older brother, she must like to get her own way.
Colonel Fitzwilliam looks at her closely and asks what she has heard to suppose that Miss Darcy is any trouble. Elizabeth says that she's heard nothing at all; she was teasing.
Then Fitzwilliam reveals that Darcy convinced Bingley not to make an imprudent marriage. There were, he states, some very strong objections against the young lady. Fitzwilliam clearly doesn't realize the "young lady" is Elizabeth's sister.
Elizabeth gets mad but tries not to show it. She guesses that the objections must be due to her family, that Jane does not come from the right social class.
Elizabeth grows increasingly upset until she has such a headache that she can't go to tea at Rosings with the Collinses.