The very morning of Miss Darcy's arrival, she and Mr. Darcy come to call on Elizabeth and the Gardiners.
Elizabeth is anxious, worried that she won't please Miss Darcy and wanting to very much.
Her nervousness, and the Darcys' arrival, make the Gardiners realize that something is afoot – that perhaps Mr. Darcy thinks more of their niece than has been suspected before.
Upon observing the two together, it's clear to the Gardiners that Mr. Darcy is in love with Elizabeth.
Elizabeth soon realizes that Miss Darcy is not proud, only very shy.
Mr. Bingley arrives, glad to see them all. Elizabeth scrutinizes his behavior towards Miss Darcy and is glad to see that nothing that would indicate that he's remotely romantically interested in the girl.
Before they leave, the Darcys invite everyone to Pemberley for dinner the night after next.
Bingley is pleased and says he has a lot to talk to Elizabeth about, wanting to inquire after all their acquaintances in Hertfordshire. Elizabeth realizes that he wants to talk to her about her sister.
The Gardiners soon discover that people in Lambton have a great opinion of Darcy, while they don't have many kind words for Wickham. They think that's telling. If anybody would know whether Mr. Darcy is actually cruel and unjust, it would be the people who have lived near him all his life.
Elizabeth stays awake that night, examining her feelings towards Mr. Darcy. The overwhelming emotion she feels is gratitude – gratitude that he loved/loves her enough not to hold her petulant behavior against her.
Elizabeth and Mrs. Gardiner decided earlier in the evening that Miss Darcy's striking hospitality requires a response, so they will visit her the next morning.