To Mr. Darcy it was welcome intelligence – Elizabeth had been at Netherfield long enough. She attracted him more than he liked – and Miss Bingley was uncivil to her, and more teasing than usual to himself. He wisely resolved to be particularly careful that no sign of admiration should now escape him, nothing that could elevate her with the hope of influencing his felicity; sensible that if such an idea had been suggested, his behavior during the last day must have material weight in confirming or crushing it. Steady to his purpose, he scarcely spoke ten words to her through the whole of Saturday, and though they were at one time left by themselves for half-an-hour, he adhered most conscientiously to his book, and would not even look at her.

– Jane Austen

Pride and Prejudice, Chapter 12. Poor Mr. Darcy, his heart has been drawing him towards Elizabeth during her stay at Netherfield, but his head is cautioning him that this is a bad idea. Darcy still hasn’t overcome his class prejudice against the low connections of the Bennets. So he is relieved when he hears that Elizabeth and Jane are soon to return home, he makes up his mind not to encourage Elizabeth for the remainder of her stay. He hardly speaks to her all day and when they are left alone briefly he buries himself in a book and ignores her. Darcy may be able to conceal but he cannot deny his strong attraction, for when Caroline Bingley is uncivil to Elizabeth his first instinct is to be protective of Elizabeth.