Elizabeth realizes that Miss Bingley has always been fueled by jealousy, so she (reasonably) wonders what to expect when she arrives at Pemberley. The answer turns out to be a cold welcome and some studied indifference – although she notices that if she speaks with Miss Darcy too much, Miss Bingley's claws start to show.
They do not come out, however, until Mr Darcy joins the party. Seems he was content to fish with the guys until Mr Gardiner mentioned that Mrs Gardiner and Lizzy were paying his sister a call, whereupon he (presumably) threw his rod into the stream and bolted for the house. He obviously wants to talk to Elizabeth, but more than that, he wants to further the acquaintance between Elizabeth and his sister.
I love that Elizabeth spent so much time prior to his appearance wondering if she'd see him, and wondering which emotion prevailed: hope or dread. On his appearance, she decided hope had won out, only to regret his appearance once Miss Bingley goes on the offensive.
Miss Bingley gets catty
Once Darcy turns up, all eyes are on Elizabeth and Darcy – and Elizabeth quickly resolves to behave naturally, knowing that she's under serious surveillance. Miss Bingley, noting Darcy's marked interest in Elizabeth, sets out to embarrass Elizabeth by bringing up the militia (thereby hinting at Lizzy's prior interest in Wickham):
"Pray, Miss Eliza, are not the ____shire militia removed from Meryton? They must be a great loss to your family."
MRRROWWWW! *claw slash*
Darcy's color is heightened, Georgiana is upset, and Elizabeth wisely doesn't rise to the bait. Darcy is relieved, Georgiana is pacified and really, the only person left upset is Caroline Bingley. Except that maybe Darcy is left a bit annoyed with Miss Bingley for being, y'know, a bitch.
Darcy walks Elizabeth and Mrs Gardiner to their carriage, and Miss Bingley immediately launches an attack on Elizabeth's appearance – only Georgiana refuses to play along, relying on her brother's judgment that Elizabeth is wonderful. Not to be deterred, Miss Bingley launches a full offensive upon Darcy's return:
"How very ill Eliza Bennet looks this morning, Mr. Darcy," she cried; "I never in my life saw any one so much altered as she is since the winter. She is grown so brown and coarse! Louisa and I were agreeing that we should not have known her again."LOL!
However little Mr. Darcy might have liked such an address, he contented himself with coolly replying that he perceived no other alteration than her being rather tanned -- no miraculous consequence of travelling in the summer.
"For my own part," she rejoined, "I must confess that I never could see any beauty in her. Her face is too thin; her complexion has no brilliancy; and her features are not at all handsome. Her nose wants character; there is nothing marked in its lines. Her teeth are tolerable, but not out of the common way; and as for her eyes, which have sometimes been called so fine, I never could perceive any thing extraordinary in them. They have a sharp, shrewish look, which I do not like at all; and in her air altogether, there is a self-sufficiency without fashion which is intolerable."
Persuaded as Miss Bingley was that Darcy admired Elizabeth, this was not the best method of recommending herself; but angry people are not always wise; and in seeing him at last look somewhat nettled, she had all the success she expected. He was resolutely silent however; and, from a determination of making him speak she continued, "I remember, when we first knew her in Hertfordshire, how amazed we all were to find that she was a reputed beauty; and I particularly recollect your saying one night, after they had been dining at Netherfield, "She a beauty! -- I should as soon call her mother a wit." But afterwards she seemed to improve on you, and I believe you thought her rather pretty at one time."
"Yes," replied Darcy, who could contain himself no longer, "but that was only when I first knew her, for it is many months since I have considered her as one of the handsomest women of my acquaintance."
He then went away, and Miss Bingley was left to all the satisfaction of having forced him to say what gave no one any pain but herself.
For an enjoyable diversion, if you have about 8-1/2 minutes, you can watch the BBC production, which actually begins at the 50 second mark (unless you want to watch the opening credits) by clicking this link – embedding is disabled for this particular video.