The mother of a young girl Fanny Bertram could have been a lady of high society, but due to her fierce love to a sailor and a marriage out of aristocracy, she ends up in poverty. Her husband is now disabled, abusive and heavily drinking, their family is too big and the poor woman is so exhausted with constant pregnancies and housekeeping that she asks her sister (who is still a member of the upper crust of the society) Lady Bertram and her husband Sir Thomas to take at least one of her children to their house. That’s how Fanny ends up in the mansion of her prosperous aunt and uncle named Mansfield Park.
But even despite now she is well-fed and properly clothed, little Fanny is still mistreated. Her aunts are ignorant at best (Lady Bertram herself) and abusive at worst (her sister Mrs. Norris who keeps the household). Her cousins, Maria and Julia, are beautiful, but shallow, spoiled and cruel. They think only about looking pretty, behaving properly, finding a good husband and spending his money away for more luxury. The story starts to resemble a lite version of “Cinderella” - Fanny grows up kind and compassionate, but too shy and with low self-esteem. Her older cousin Tom is already a drunkard, who likes to spend time having fun and nothing more. The only her friend in the whole estate is the youngest son of Lady Bertram and Sir Thomas. His name is Edmund and he is equally kind and shy. Edmund chose to pursue a career of a clergyman.
The time passes and all the youngest children reach their adolescence. It is the time for the girls to shine and attract the rich and beautiful suitors. When Sir Thomas leaves for long to check his plantations in America, Maria and Julia take every opportunity to do this without parental control. Especially after the local minister’s family welcomes back their children, Henry and Mary Crawford, who are roughly the same age. They are beautiful and intelligent and soon none of the Bertrams events is held without them. Henry flirts heavily both with Maria and Julia switching between sisters whenever he wants. He ignores the fact that Maria is already engaged with rich but very plain and boring Rushworth. Mary at first tries to court Tom, but quickly sees that he is boring too and isn’t interested in marriage in general and in her in particular.
Fanny and Edmund are lost between all the love triangles happening around and gradually Fanny falls in love with him - so innocently that at first she herself can’t recognize these feelings as love. But their time spent alone ends soon: Mary, disappointed with Tom, switches her attention to Edmund, wanting to marry at least any of the brothers. But she is extremely displeased with his career choice and often cruelly berates him for decision to become a clergyman.
Meanwhile the friend of Tom named Yates arrives and they all go to the house of Mr. Rushworth to visit Maria’s future husband. But there the flirting of Maria and Henry crosses the line a bit. Returning home they decide to do something at home. Yates offers to prepare a play named Lover’s Vows written by Elizabeth Inchbald, that has some dubious and almost erotic content. Everyone is excited with the idea except Fanny and Edmund who are too shy to play and outright horrified by the scenes of love between the characters.
When they start to play, Edmund is still forced to play to avoid inviting outsiders to the performance. He is incredibly embarrassed with his role but still works on it. When one of the girls is unable to perform for some reasons, Fanny is also forced to take her place. When she gives up and almost enters the play, Sir Thomas finally returns from his American voyage and sees all the improprieties that his children are engaged in. He strictly berates everyone and dismisses the “actors”. The teenagers return to their previous activities trying to act modestly again. Henry, as the most active of them, quickly departs, leaving both sisters extremely upset. Maria, who is devastated with this uncertainty finally decides to marry Mr. Rushworth. They leave for a honeymoon travel, taking Julia with them. It becomes a bit calmer in the house.
Edmund finally falls for Mary’s advances. He even makes several attempts to make her a proposal, but stops in the very last moment, remembering about her morally dubious behaviour and bad nature. He even discusses his feelings and troubles with Fanny. It is hard to listen for the poor girl, but she is still too shy to confess herself and only wants Edmund to be happy, attentively listening to him, telling he is in love with another girl.
Another sudden turn happens when Henry returns to the Mansfield Park, quite aggressively trying to court Fanny - the only one who wasn’t charmed by him on the spot. Fanny, to his surprise, is not interested in him at all, even despite Edmund made his choice. Gradually, to his own surprise, Henry develops a genuine interest towards her. Even Sir Thomas start to press Fanny to consider him as a future husband. Mary, in her turn, tries to befriend Fanny too, as Edmund’s best friend, but Fanny is not amused for obvious reasons.
Eventually, Fanny’s brother William arrives to the Mansfield Park. He overcame his family’s poverty and now is a promising young man who is going to go to the Navy. The Bertrams conduct a ball to greet him, and Fanny suddenly becomes a star of the ball, so stunning that Henry is ready to marry her immediately. He talks to William and, using his connections, promises to promote him in the Navy. Later Henry uses it to try to press Fanny into marriage, seeing that she is very concerned with the fate of her brother. But even now Fanny is adamant: she refuses with disgust, feeling that Henry’s actions are incredibly dishonest. It doesn’t stop him though and finally Sir Thomas outright orders her to marry him. After her final refusal Sir Thomas sends her away to her former home as a punishment, extremely disappointed that Fanny lost the possibility to marry the wealthy and handsome man out of (as he thinks) sheer stubbornness. Fanny doesn’t object.
She returns home and understands that despite all the mistreatment she got in the Mansfield Park, that estate became her true home. Henry follows her even there, now introducing himself to her real parents with the same purpose. Fanny continues to receive letters from Mary (who is still pretending to be friendly and is trying to persuade her to finally marry Henry) and from Edmund who is still hesitating and asks for advice and compassion.
Henry finally leaves and Fanny starts to receive another news from the Mansfield Park. At first Tom, the oldest brother, catches a dangerous illness and almost dies. Henry, still being a womanizer, hangs a bit with his friends and returns to (already married) Maria, taking her somewhere with him. Julia, shocked and upset with such a behaviour of her sister, elopes with Yates (the one who arranged the scandalous play). Sir Thomas finally forgives Fanny, after seeing that she was right about Henry and invites her back to the Mansfield Park. Fanny indeed returns but brings with her a younger sister named Susan, hoping that she too can give the girl a better life.
There she meets heartbroken Edmund. He dumped Mary, because, when Tom was ill, she finally showed her true self, rejoicing his dangerous condition. She hoped that Tom would die and Edmund would become the only heir of all the mansion. Also Mary was the only one who saw the actions of her brother as something acceptable until he has enough wealth. Fanny wholeheartedly soothes him.
Maria and Henry’s relationship doesn’t last long. Very soon Maria leaves to live somewhere else with Mrs. Norris (the housekeeper who mistreated Fanny). Now the atmosphere in the house is much better, especially after Yates and Julia are forgiven and accepted back to the family. In the next generation Susan takes Fanny’s place, but her starting conditions are much better. And finally Edmund sees that Fanny loved him all along and proposes to her. She gladly accepts and they marry.