The narrator likens critics to reptiles and tells the reader not to judge the work too soon. The reader should not mind if he finds characters too similar. It is natural for characters—like humans—to be akin in many aspects. In fact, there is more refinement in the critic who can distinguish between more closely aligned characters.
An Irish Gentleman, Mr. Fitzpatrick, arrives at the inn that night looking for his wife. The maid leads him to Mrs. Waters's room. Fitzpatrick breaks down the door and Tom leaps out of bed. The man apologizes for making a mistake, but then sees the room strewn with women's clothing and attacks Tom. Another Irishman, Mr. Macklachlan, who knows Fitzpatrick, runs in and points out that the woman is not Fitzpatrick's wife. The landlady arrives and Mrs. Waters accuses all three men of breaking into her room to violate and kill her. Fitzpatrick asks pardon for his mistake and leaves. Tom tells the landlady that he was trying to save Mrs. Waters.
A brief history of Mr. Fitzpatrick is given. He married for money and spent his wife's fortune, then treated her so badly that she ran away from him. A post-boy arrives at the inn with a young lady and her maid. The lady very politely asks if she may retire for a couple of hours. Her manners are magnificent, and she does not want any one to be disturbed. The landlady tells the maid Susan to light a fire in the Rose room. Once the lady and her maid leave, the company falls to praising the beauty of the lady's face, dress, and manners.
Mrs. Abigail, the young lady's maid, demands a hearty feast. She does not act with the gentility of her mistress, but greedily occupies most of the space before the fire. She asks the landlady whether it is true that her house is filled with "People of great Quality." The landlady cites the young squire Allworthy as an example. Mrs. Abigail expresses great surprise, saying that she knows the squire Allworthy very well, and he has no sons. Partridge says the young man is not generally acknowledged to be the Squire's son, but that he is most certainly the Squire's heir, and that his name is Jones. Mrs. Abigail drops her bacon and hurries to tell her mistress.
The young lady eulogized in the previous chapter is Sophia Western herself, and the so-called Mrs. Abigail is Mrs. Honour. Honour scurries to tell Sophia that Tom is in the house. Sophia sends Honour to request Tom's presence, but Partridge, who is tired and drunk, tells Honour that Tom is in bed with a "wench." Sophia bribes the maid Susan to see whether Tom is in his own bed, and Susan discovers that he is not. She tells Sophia that Partridge has told everyone that Sophia is madly in love with Tom, who is heading to fight in the wars to escape her. In tears, Sophia tells Honour it is now easy for her to leave. She can forgive Tom's behavior with the wench, but not his misusing her name. Sophia leaves her muff with her name on a piece of paper pinned to it in Tom's bed as "some Punishment for his Faults."
Partridge tells Tom he would rather not fight in the rebellion, but that if they must, Tom should at least let him steal horses so they do not have to walk. They argue and Partridge lets slip that the previous night he had to bar two women from getting to Tom. He points out that one of the ladies has left her muff on Tom's floor. Frantically, Tom demands to know where the women have left for and orders the horses. Maclachlan suggests that the lady who arrived the previous night might have been Fitzpatrick's wife, who he has yet to find. A gentleman enters the kitchen just as Fitzpatrick is returning.
Squire Western has arrived in pursuit of his daughter. The kitchen is filled with confusion as Western asks for Sophia and Fitzpatrick searches for his wife, who is also Western's niece. Tom enters holding Sophia's muff. Western attacks Tom and Parson Supple, who has accompanied Western, points out that Tom has Sophia's muff. Western charges the house and bursts into Mrs. Waters's room. Fitzpatrick argues that the stolen muff represents a felony, and a "trial" ensues. Tom's witnesses are Susan and Partridge, and he is acquitted. Western departs to follow Sophia, as do Tom and Partridge.
The narrator retraces his steps to the morning after Sophia made her escape. A serving-man, sent to summon Sophia to meet Blifil, returns to say that Sophia cannot be found. Mrs. Western launches into a grand speech in which she blames her brother for Sophia's disappearance. She says that English women are not to be bullied in such a way.
The night before these events, Sophia courageously escapes at midnight. She meets Mrs. Honour at their prearranged place of rendezvous, a town five miles away. Honour wishes to head straight for London, but Sophia, hearing from her guide that Tom journeyed to Bristol, pays the guide to take her there. In Hambrook, Sophia and Honour meet Mrs. Whitefield, who tells them how much Jones has spoken about Sophia. Honour wrathfully calls Tom a "saucy Fellow." Mrs. Whitefield advises Sophia not to chase any man, but the narrator says he can forgive her due to her tumultuous state of mind, which is torn between her duty to her father, her hatred of Blifil, and her love for Tom. En route to London, Sophia and Honour happen to rest at the Inn at Upton, where the uproar of Chapter V occurs. Western has been able to track down his daughter by following Tom's trail, which Partridge has made as public as possible by announcing Tom to everyone he meets.
Book X witnesses the converging of most of the main characters at the inn at Upton as the raucous comedy of errors unravels. This book brings Tom, Sophia, Mrs. Waters, Fitzpatrick, and Western into the same physical space without having them congregate at the same time.
It is notable that Fielding leaves Sophia and Honour unnamed at first—they are simply a "young lady and her maid," and this delay suggests that we should judge characters not by their names and titles, but by their disposition. The landlady in Chapter II of Book XI, for example, assumes that Sophia is not a gentlewoman since she is courteous to the servants but this precisely one of the values Fielding is trying to promote in Tom Jones.
Sophia is not as concerned with the fact that Tom is sleeping with other women as she is with the fact that he is misusing her name. Reputation determines social standing at this time. Fielding shows how much freer women like Mrs. Waters are with their bodies than they are with their reputations. Fielding does not criticize Mrs. Waters, however, and when she embellishes the comedy of the scene in which Fitzpatrick barges in on her and Jones, she is to be admired for her ingenuity rather than criticized for her lack of chastity.
In Chapter I, the narrator preempts critics who might object to the faults and follies of his characters. He thus warns the critic "not to condemn a Character as a bad one, because it is not perfectly a good one." The narrator, claiming that he has never encountered a perfect person in conversation. Fielding was known to converse with people of all types and his knowledge of people's manner of acting and speaking reveals itself particularly in his characters' realistic dialogue.