Fanny is overjoyed to see her brother William when he visits Mansfield Park, and spends every possible moment with him. Henry Crawford is impressed with their mutual devotion, and comes to view Fanny in a new light. He thinks how wonderful it must be to be loved like that, and soon falls in love with her. Fanny remains oblivious to Henry's feelings for her, but Sir Thomas becomes aware of the amount of attention that the infatuated Henry has been paying her. Henry does everything he can to get Fanny to notice him, including teaching her a card game called "Speculation" after a dinner party, in which Henry recounts for Edmund his accidental visit to Thornton Lacey, where Edmund is set to take on the job as pastor. Mary is crestfallen: she cannot believe that Edmund is actually becoming a pastor, and the thought of having him living away from Mansfield is too much for her to bear. Fanny also is saddened by Edmund's looming departure. At this point, William voices disappointment over the fact that he has not yet attained the rank of lieutenant, telling Fanny, "The Portsmouth girls turn up their noses at anyone who has not a commission. One might as well be nothing as a midshipman." William is leaving shortly, and he tells Fanny how much he would enjoy seeing her dance before he goes. Sir Thomas overhears this and immediately sets about organizing a ball for the Prices, Fanny, and William.
The whole house is busy preparing for the ball and for Edmund and William's departure. Edmund vacillates back and forth about Mary: he wants to ask her to marry him before he leaves, but is fearful: "the issue all depended upon one thing. Did she love him well enough to forgo what used to be essential points-did she love him well enough to make them no longer essential? And this question, which he was continually repeating to himself, though oftenest answered with a 'Yes,' had sometimes its 'No'." Fanny is also worried about how to properly wear the amber cross William has given her as a gift, since she has no chain for it. On the way to ask Mary for advice, she runs into Mary, who coincidently was on her way to offer Fanny her choice of chains. Stunned by her kindness, Fanny accepts one, only to learn that it was a gift from Henry to his sister. She hesitates, but Mary insists that she accept it. Later, Edmund also presents Fanny with a chain, and she is overwhelmed by such a display of goodness. He tells her that she should accept Mary's chain so as not to hurt her feelings. However, when she realizes the depth of Edmund's feelings for Mary, she is heartbroken.
Edmund visits the parsonage to ask Mary to keep the first two dances open for him, and once again she denigrates his choice of occupation. In response to her attitude, he withholds his proposal of marriage. The problem concerning the chain is solved when Fanny discovers that the cross will not fit through the ring of Mary's chain. She must use Edmund's chain for the cross, but ultimately decides to wear both chains. Lady Bertram makes a fuss over Fanny by sending her personal maid, Mrs. Chapman, to help Fanny dress even though Fanny has already finished dressing herself.
To Fanny's great consternation, she has been selected to open the ball. She must lead the dancers, and is extremely intimidated by the importance of the task that has been assigned her. Fanny is, after all, shy, and prefers to remain on the margin rather than take center stage. Although everyone at Mansfield misses Maria and Julia, Fanny for once feels that she is being treated as well as her missing cousins. To Fanny's extreme delight, Henry has made arrangements for William to share his own carriage to return to his ship, the Thrush, which is ready to set sail out of Portsmouth. Henry also has surprised William by arranging an interview for him with his uncle, the Admiral. Naturally, both Fanny and William are overwhelmed with gratitude towards Henry. Fanny sadly leaves the ball early so that she can be up early and have breakfast with William. Sir Thomas peruses the crowd, and cannot help but become aware of Henry's affections for Fanny.
Fanny is saddened by William's departure, but heartened by Henry's absence. Sir Thomas assumes that some of her tears are for Henry Crawford, but Fanny feels only relief that he has left: "William was gone, and she now felt as if she had wasted half his visit in idle cares and selfish solicitudes unconnected with him." Everyone, however, misses Edmund, who has gone off to take his orders. Fanny becomes ever more dear to the Bertrams, who discuss her remarkable qualities and marvel at how well she turned out. Meanwhile, Mary Crawford misses Edmund enormously, and wonders why he is staying away longer than expected. She visits Fanny for information about him and learns that he is staying with another clergyman, who happens to have two attractive, single sisters. Fanny realizes the depth of Mary's feelings for Edmund, and is once more saddened. That night, Henry returns from London. After visiting Mansfield for an hour and a half, he returns to the parsonage to tell Mary that he has decided to marry Fanny. She is delighted with the news, believing Fanny to be the perfect woman for Henry, and sees the union as a way for her to be close to Edmund. However, she recalls how her brother tinkered with the hearts of Maria and Julia, and wonders at their reaction. Henry dismisses her reservations, but she doesn't for a single moment consider the possibility that Fanny might not accept Henry.
The two chains symbolically represents the contest between two men: Henry, whose chain indirectly winds up in Fanny's hands, and Edmund, whose direct gift of a chain she favors. Symbolically, Fanny must choose who she will be bound to, but only one chain fits her properly: Edmund's. However, she does not currently have the ability to make a concrete choice in the matter: for a time, she wears both, and carries on an attachment with both men. At this point, any outcome is possible. The result of the connections could be two married couples, one married couple, or no married couples.
Fanny is stuck between two men: Edmund, whom she loves with all her heart but more than likely will never attain, and Henry, who comes with the promise of high social rank and a luxurious lifestyle. Edmund is similarly stymied. He loves Fanny, but Mary Crawford attracts him sexually. After all, he was brought up to think of Fanny as a sister. Edmund's sexual attraction has in the past tempted him to forgo his better judgment, and he is now tempted to dismiss his anticipated career out of his desire to please Mary Crawford. Mary wavers about her feelings for Edmund: while it appears she does love him, she does not love the path he wishes to follow. In addition, she remains angry that he plans to move to a parsonage eight miles away and perform the parish duties rather than live at home at Mansfield.
Henry believes that Fanny will transform him into a man of honor. He has come to admire the heroic William Price, who unlike himself works hard instead of living an indolent life. By loving him as she loves her brother, Henry believes, Fanny will set high moral standards that he will be able to emulate: "her understanding was beyond every suspicion, quick and clear, her manners were the mirror of her own modest and elegant mind. Nor was this all...such a high notion of honour, and such an object of decorum...well principled and religious." Fanny is painted as the picture of perfection, someone who could well be the person who could reform Henry Crawford, but there is nothing in his past nor in his present demeanor to suggest that he could or would ever truly want to be reformed.
Henry's proposal to a woman of Fanny's social position should not be underestimated. He is, after all, the sole heir to an estate, and Fanny would be raised far above her present position in society. Indeed, were she to marry Henry she would never know want, and would vastly improve the living conditions of her family. Mary Crawford realizes that Fanny is the perfect woman for Henry, but her delight shouldn't be underestimated: Mary Crawford sees things on many levels, and understands that a closer association with Fanny Price would bring her closer to Edmund Bertram. Henry's dismissal of Mary's reservations is absolutely correct: "Yes, Mary, my Fanny will feel a difference...in the behavior of every being who approaches her and it will be the completion of my happiness to know that I am the doer of it, that I am the person to give the consequence so justly her due. Now she is dependent, helpless, friendless, neglected, forgotten."