Mary is delighted when her brother Henry returns to Mansfield Park. She hopes to find out the reason he had left. Before she can get an answer, Henry excuses himself from her company and goes to visit the Bertrams. When he is gone more than an hour, Mary is astonished. What could he be doing there?

Henry does not keep Mary waiting too long for an answer. Upon returning to the parsonage, Henry has nothing to do but talk of Fanny. He describes how beautiful Fanny is looking and finally confesses to Mary that he is determined to marry Fanny.

At first, Mary is bewildered. The thought of her brother marrying Fanny had never crossed her mind. She had known that he was attracted to Fanny, and she had warned him not to hurt Fanny with his usual flirtatious games, but she did not think his feelings for Fanny would extend to a proposal of marriage. Fanny, though beautiful and demure, was beneath him. It did not take long, though, for Mary to come to accept Fanny as a potential sister-in-law. Henry's connection to the Bertrams would only help to make her prospects of marrying Edmund much stronger.

Henry continues to talk only of Fanny and about how much he wants her. He does admit that so far Fanny has shown no sign that she will accept him. Mary thinks this foolish. How could Fanny resist? What an honor it would be for Fanny to marry Henry. What amazing luck Fanny has had throughout her life, first to be taken in by the Bertrams and now to become a part of the Crawford family.

Mary finally makes a connection between Henry's love of Fanny and his visit to London. She insists that Henry went to the city to tell their uncle, the admiral, of his pending engagement. Henry denies this, saying that the admiral would be one of the last people to know. Their uncle is against marriage, seeing it as the ruin of any man. But Henry refuses to tell Mary his reason for the trip. She will have to wait, he tells her.

Mary is content. The news of Henry's love for Fanny is enough for her. Although she would not have chosen Fanny as Henry's wife, the more she considers it, the better the match appears. She tells her brother that Fanny will not marry him unless she loves him. But all he has to do, because Fanny has such a tender heart, is to ask her to love him. Fanny will not be able to resist.