Beautiful, clever, and rich Emma Woodhouse is convinced she is good at matchmaking after her older sister and her governess both marry suitable husbands. No matter that as Mr Knightley dryly observes, in reality, she had nothing to do with these relationships. Yet Emma, certain of her talents, plays a dangerous game as she persuades her new friend, the young, pretty and socially inferior Harriet to reject an advantageous marriage proposal to a local farmer in favour of dashing Mr Elton. So begins a story which challenges Emma's naivety, her social preconceptions and her relationship with Knightley.
Rich, independent and kind-spirited, Emma Woodhouse has no need to marry, but nothing delights her more than matchmaking those around her. Once she has married off her close companions, she alights upon the pretty Harriet Smith to fashion into her new playmate and ally. She persuades Harriet that she is too good for her suitor, the farmer Robert Martin, and encourages her to set her sights higher. But close family friend Mr Knightley warns Emma that her meddling will cause great pain - to both Robert and Harriet. Emma refuses to listen, and Mr Knightley is furious at Emma's stubbornness.
Emma continues her attempts to marry off Harriet and Mr Elton, vicar of Highbury. Although uninterested in marriage herself, she is intrigued by the mysterious and elusive Frank Churchill, who she hopes to meet for the first time at a village Christmas party. Frank does not arrive, and instead Emma becomes the subject of unwanted and embarrassing attention from Mr Elton. A few weeks later, village gossip and speculation focuses on the arrival of young Jane Fairfax and a large piano she has been sent by a mystery admirer. Emma refuses to believe that Mr Knightley could be the secret admirer. He couldn't be, could he?
Emma teases Mr Knightley about Jane, but he remains tight-lipped. Meanwhile, Frank and Emma plan a ball, and Emma wonders whether she might be in love with him. Despite having a wonderful time at a village ball, she decides not. With her matchmaking officially abandoned, Emma feels cooped up and bored, so Mr Knightley suggests a day trip to Box Hill for a change of scene and some temporary escape. He also tells Emma that he suspects Frank and Jane to be secretly in love. Emma rebuffs the suggestion - she can personally vouch for Frank's indifference to Jane - which leaves Knightley feeling hurt at Emma's indifference towards him.
What was intended as a day of fun turns into a day of agony for everyone on the Box Hill excursion. Things come to a head when, egged on by Frank, Emma behaves very badly, insulting Miss Bates. She is berated by Knightley, and realises that her behaviour was shameful. She tries to repair things with Jane and Miss Bates, but Jane will not see her - although Miss Bates tells her that Jane has accepted a job as a governess, and cried all night. Meanwhile, Knightley goes to stay with his brother in London, and will be away for a while. When Frank's controlling aunt dies, the Westons expect him to propose to Emma - but his actions set in motion a chain of events that both shock Emma and make her realise something that has been in plain sight all along...