This installment begins with a flashback about Dr. Swishtail's school. Students have snubbed William Dobbin because his father is a retail grocer. Dobbin has crossed Cuff, the bully of the school, when he tries to take Dobbin's letter away from him. Later Dobbin stops Cuff from beating George Sedley Osborne. In the ensuing fight young Dobbin defeats Cuff.
Dobbin's victory over Cuff has gained his acceptance by the students and the lifelong friendship of George Osborne. This history explains why George invites William, now of His Majesty's ____th Regiment of Foot, to the Sedley house the night of the party at Vauxhall. Dobbin's father has become a rich alderman, consequently he and his family are respected everywhere.
As the evening progresses, Becky catches George admiring himself in the mirror. Joseph Sedley assumes a courteous manner and opens the door with the "most killing grace." All three are actors in Vanity Fair.
Chapter 6 opens with the author making fun of writers. He then describes the evening at Vauxhall, when everyone thinks Joseph will propose to Becky. Mr. Sedley, contemptuous of his son, thinks Becky better than a black daughter-in-law. Amelia has discussed the affair with Mrs. Blenkinsop, the housekeeper, and everyone talks of Joseph's marriage. At Vauxhall, Dobbin carries the shawls; the others pair off. Joseph drinks too much and makes a fool of himself. George takes the girls home; Dobbin takes Joseph home.
The next day Joseph has a terrible hangover. George, Dobbin, and Sedley's valet make him think he has been a veritable lion the night before. Then Osborne tells him the truth, that he was maudlin and couldn't stand up. George mimics Joseph's treatment of Rebecca. George later tells Dobbin that he would rather have a lady for a sister-in-law, that Rebecca should know her station, and that Dobbin can make love to her. When George returns to Sedleys and says Joseph isn't coming, Becky recognizes that George is her enemy. Amelia sends a messenger to Joseph and finds he is ill.
On the arrival of Joseph's letter saying that he is leaving for Scotland, Rebecca knows she is beaten. Blenkinsop, the housekeeper, consoles Amelia by telling her that Becky has read Mrs. Sedley's mail and stolen a ribbon. In vain Amelia defends Rebecca. Everyone, except Amelia, knows it is time for Rebecca to go. On Amelia's insistence Mr. Sedley and George give Becky presents; she departs for the Crawleys, who are supposed to be of a higher status than the Sedleys.
Rebecca is trying to visualize a baronet, Sir Pitt Crawley, when they arrive at Great Gaunt Street. The coachman hates Rebecca because she does not tip and because Amelia has given her some dresses he hoped his girl friend would get. He tells the old fellow who is looking out of the Crawley's window to unload Becky's trunks. The old fellow who turns out to be Sir Pitt, the baronet, helps. Tinker, the housekeeper, and stingy Sir Pitt eat, but do not ask Becky to join them.
Rebecca tries in vain to get information from Tinker. The next morning Rebecca and Sir Pitt catch the stagecoach for Queen's Crawley.
Chapter 5 shows that snobbery begins early in Vanity Fair. Dobbin's schoolmates shun and laugh at him because his tuition is paid in goods. Osborne thinks himself better than Dobbin because Osborne's father is a gentleman and keeps a carriage. Even when Dobbin fights for Osborne, the latter is ashamed of him.
After Dobbin whips the bully, Dobbin improves in scholarship; his father, for the first time, respects him and publicly gives him money.
Still snobbish as a young man, George says he doesn't want a governess for a sister-in-law. Although he may have been joking when he suggests Becky is good enough for Dobbin, the reader may feel that George's real attitude toward Dobbin is condescension even though Dobbin's father is now a knighted alderman. Becky sees that George has prevented her marriage and "she loved George Osborne accordingly." Aside from Dobbin, the only admirable person so far is Amelia, and she appears too simple and innocent to be interesting.
Thackeray lets his characters reveal themselves by words. Mr. Sedley remarks that if all the family should die, Joseph would say, "Good Gad!" and go ahead with his dinner. Thackeray also shows them in action. "Jos squeezed through the gate into the gardens." Rebecca flirts with Joseph; when someone steps on her foot she falls "back with a little shriek into the arms of Mr. Sedley, and this little incident increased the tenderness and confidence of that gentleman to such a degree, that he told her several of his favorite Indian stories over again for, at least, the sixth time." Amelia looks "as happy as a rose-tree in sunshine." Thackeray points out that Rebecca cries only so long as the Sedleys can see her; she despises them now that she has failed to get Joseph.
Loathsome as Sir Pitt is, he has the refreshing characteristic of making no pretenses, and in this, he is something like Mr. Sedley. Both have enough money to scorn the opinion of society.
Characteristic of Thackeray's frequent reversion to the essay, he begins Chapter 6 with rambling observations directed to the reader, telling how he might have changed the story; he closes the installment with a discourse on how times have changed.
Part of the conflict in Vanity Fair arises from the frantic, often questionable, struggle of all characters, except Dobbin, Amelia, and Briggs (who will be introduced later) to rise in social and financial power. Plot centers around conflict; Thackeray loses no opportunity to point out this struggle. He satirizes the naming of children after celebrities, and mentions the Crawley ancestor, the first baronet of the Tape and Sealing-Wax Office, who was impeached for embezzlement — as were other honest gentlemen.