Charles turns to Julia’s role in his story. He has always had some interest in Julia because she looks so much like Sebastian, and as Sebastian declines, he notices Julia more and more. Charles now regrets not going to a ball at the London Marchmain house during Julia’s first season in society. He had thought that he would have time later to enjoy London society.
Not long into her first season, Julia begins strategizing about making a good marriage. Although she stands out with her looks and personality, her Catholicism prevents her from marrying into a desirable family. However, she believes converting to Protestantism would send her to hell.
When she meets Rex, she’s impressed by his demeanor and his ability to join prestigious social circles. Because he’s from Canada, Rex has a unique position in society that makes him seem mysterious. Realizing that Julia is a good marriage prospect for him, Rex works on getting close to her by offering assistance to her and her family. This strategy eventually wins her heart. Soon, Rex proposes.
Lady Marchmain doesn’t approve of their engagement because she doesn’t trust Rex. Julia continues the relationship in secret, leading Rex to continue an affair with an old flame, who is a married woman. Rex claims Julia has left him with no choice because she “gives so little.” Julia asks her priest in confession whether there is a way that committing a small sin to prevent a larger one could be acceptable. When he says no, she temporarily renounces Catholicism. After Julia refuses to take communion at Christmas—the same Christmas of Sebastian’s drunken escape—Lady Marchmain forbids her engagement to Rex. But Lord Marchmain, impressed with Rex’s prosperity and pleased that Lady Marchmain doesn’t like him, agrees to the marriage.
Because Rex and Julia’s marriage will be considered mixed—between a Protestant and a Catholic—their wedding will be small, infuriating Rex. He decides to convert to Catholicism. Lady Marchmain doesn’t believe Rex is sincere in his faith, and the priests agree that he’s attempting to convert without understanding the substance of conversion.
Bridey discovers that Rex has been married once before, and because the church frowns upon divorce, Rex cannot convert to Catholicism. Rex argues that the priests don’t know about his marriage, so it doesn’t matter. Julia agrees, infuriating Cordelia. Rex suggests they get married in a Protestant church. Lady Marchmain forbids it. Julia scandalizes everyone by saying that she’s been Rex’s mistress and wants to marry him so that she can stop living in sin—a lie. In the end, Rex gets Lord Marchmain’s permission and marries Julia in tiny ceremony in a chapel often used for weddings between previously divorced people.