Emma realizes she loves Mr. Knightley

The revelation of Harriet's feelings for Mr. Knightley acts as a thunderbolt for Emma. In a flash of painful clarity, she understands her own heart. She has been in love with Mr. Knightley for a long time, and her jealousy of Jane Fairfax and her indifference to Frank Churchill were all symptoms of this deeper truth. She is filled with shame for her blindness and for the mischief she has caused by encouraging Harriet's hopes.