After leaving Ernestina's house, Charles goes to find Dr. Grogan and send him to take care of her. When he returns to his hotel, a shocked and angry Sam announces that he will not be accompanying Charles on his future travels: he wants to marry Mary and settle down. The master and servant exchange angry words, and Sam leaves. Charles begins to draft a letter to Ernestina's father.
When Aunt Tranter arrives home, she meets Dr. Grogan, who has examined Ernestina. He says that she will be "as gay as a linnet" within six months, but Aunt Tranter is horrified and insists that Ernestina will die of a broken heart (305). Aunt Tranter goes downstairs to check in on Mary, who is distraught at the news that Sam has quit his job - what is to become of the two of them? Aunt Tranter promises that she will find employment for Sam, and that Mary will not leave her service until she is settled down and married to Sam.
Dr. Grogan and Charles discuss the situation; Charles explains his motives for breaking off the engagement and apologizes for having deceived Dr. Grogan. The doctor is furious with Charles for having told lies and having made Ernestina suffer, but his feelings are slightly mitigated by his affection for Charles and his knowledge that Ernestina is too shallow to be paired with Charles in marriage. At least, he thinks, Charles will marry Sarah - and he may be forgiven by the world if he uses this opportunity to become a "better and more generous human being" (311).
Back in Exeter, Charles calls on Sarah at the Endicott Family Hotel, only to learn that she has left and gone to London, without leaving an address. He questions the hotel staff and learns that Sam never brought his letter to Sarah. Charles curses Sam in his head, and vows to spend the rest of his life searching for Sarah.
The next morning, Charles gets on a train to London. A latecomer joins him in his carriage, and the two make cold and awkward eye contact before Charles begins to fall asleep. The bearded man begins to stare at Charles intently, and the narrator admits that he is the bearded man, wondering what he is going to do with his character Charles. He says that he envisions two futures for Charles - two possible endings of the novels - and wants to show the reader both, but cannot decide which order to put them in. He flips a coin to decide. Charles wakes up and scowls at the narrator before they arrive in London and both exit the train.
In this chapter, Charles begins to get a taste of the sort of social disapproval and rejection that he decided he didn't care about at the end of his time in the church, in Chapter 48. He resolved not to care about what others think about him, because who are they to judge? However, in the space of a morning, Charles has had to deal with Ernestina's fury, Dr. Grogan's shocked horror, and Sam's disapproval. Charles feels as though he deserves such responses from Dr. Grogan and from Ernestina, and he respects them enough to accept their reactions. Sam, however, is the last straw - Charles begins to panic about what he has done, since "even his servants despis[e] and rejec[t] him!" (303).
Ernestina has a very strong reaction to the news that she is losing Charles to another woman - she swoons and has to retire to bed. However, we might suspect that her reaction isn't quite as total or genuine as it appears. At the end of Chapter 50, Charles notices there is something rehearsed in her swoon, as if she was merely performing the expected reaction of "convention" (300). In Chapter 52, Ernestina's slight pretense is exposed through comparison with Mary, who "really did look like a soul in the bottom-most pit of misery" (306). Even Aunt Tranter has to realize that Mary looks like "Tina ought to have looked, but didn't" (306). The conclusion that we can draw from careful reading here is that Mary's love for Sam is much stronger than Ernestina's love for Charles, because when faced with the prospect of losing their lover, they react to different degrees.
Dr. Grogan makes the serious consequences of Charles’ actions apparent in this chapter. He likes Charles, but he also feels sorry for Ernestina and is angry at Charles' deception. Dr. Grogan's justice is harsh but reasonable - he lets Charles know what the world will think of him (that he is a man driven by his "baser desires" and his lust) and he says that Charles deserves to be punished (311). However, there is also a chance at redemption: if Charles becomes a "better...human being," he can be forgiven his sins (311). Dr. Grogan takes the role of confessor in this chapter, which is interesting, given that Charles avoided the chance to be confessed in Chapter 49. But Dr. Grogan isn't a usual confessor - he is the secular voice of where reason and science intersect morality. He operates off the creed that "[a]ll suffering is evil," and he encourages Charles to make sure something beautiful and good comes out of the pain that Charles has caused (309). The reader likely agrees with everything Grogan says, because he presents himself as a highly reasonable and fair person in this chapter - Charles is a sinner, but can still become a good person and atone for his sins against Ernestina.
Ironically, by 'ruining' his life by having sex with Sarah and jilting Ernestina, Charles now feels he has a purpose in life: the "expiation" of his guilt (312). He seems to take pleasure in the idea that he is now "infinitely alone" and "exiled" from society, and that he has Sarah with him as a companion in his exile (313). Charles dreams of visiting exotic European locations with Sarah; we see that she still represents travel and faraway possibilities to him. Of course, when he arrives at the hotel, she isn't there - she has left without notice, and Charles is reminded that she is still a mystery to him, and that their future isn't set and settled by any means.
This chapter is fantastically bizarre and unconventional. The narrator, who has already intruded into the narrative at several points (notably, Chapter 13) to remind us that we are reading a work of fiction, here goes so far as to insert himself into the story as a character who interacts with the other characters. Fowles makes a point of noting that Sarah and Charles are just "figments of [his] imagination;" it is bizarre that he makes the effort to enter the story and interact with these characters (317). In a way, we can read this as an analogy to what the reader does when he or she becomes invested in the fates of characters who are clearly not real, but who capture our attention and our sympathy nonetheless. The narrator reiterates the analogy between him and God, and perhaps we can interpret this scene as God taking on a real/corporeal body and coming down into the world to visit his creations, as Christ visited the humans that God created.