The day after his conversation with Mrs. Crupp, David decides to go see Traddles, who lives in a neighborhood with an air of "faded gentility" that reminds David of Mr. Micawber. When he reaches Traddles' building, he finds a milkman harassing a servant girl for money she owes him. David asks for Traddles, and she directs him upstairs, where he finds Traddles waiting for him on the landing. Together, they enter Traddles's room, which is extremely cramped and crowded. David notices, however, that Traddles has made several "ingenious" accommodations to fit everything into a single room.
Like David, Traddles is just beginning to make his way in the world. However, where David has a wealthy relative to rely on, Traddles does not, and is consequently living in a lower-middle class neighborhood. The fact that he has made the most of his rooms, however, hints at an ability to better his situation in life and eventually work his way upwards.
Traddles explains that he usually invites guests to his "chambers"—an office he shares with other law students—in case they don't want to visit his apartment. He says that he is not ashamed of it, however, because he is making his way in the world, and the initial cost of becoming "articled" (apprenticed) was high.
Unlike David, who is self-conscious about both his age and his social standing, Traddles freely admits that he is just starting out on his career. This self-awareness serves him well, because it allows him to forgo unnecessary expenses (like better rooms).
David reminds Traddles of the sky-blue suit he used to wear at Salem House, and Traddles laughs about the "happy times" they had there. David attempts to remind Traddles of how cruelly Mr. Creakle treated the students (and Traddles in particular), but Traddles seems happy to let bygones be bygones.
Traddles is also a foil to David in his experience of the past. Whereas David often finds himself bogged down in memories (whether pleasant or distressing), Traddles is able to laugh over even the worst memories and then quickly set them aside to focus on the present.
David asks Traddles about the uncle who raised him, and Traddles explains that he was a cloth-merchant who died shortly after he finished school. This uncle had intended to make Traddles his heir, but took a disliking to him once he had grown up. Traddles does not seem disturbed by this, however, and matter-of-factly recounts that he was left with only 50 pounds when his uncle died, and no sort of job training. Fortunately, he was able to use a contact from Salem House to get a job copying law writings. From there, he progressed to writing up cases and then eventually decided to study law himself. He has also been making a little money helping to compile an encyclopedia; he views this work as a good fit, because he says he has "no invention at all; not a particle."
Traddles may be early on in his legal studies, but he's already come a long way from his starting point: through patience and hard work, he has managed to work his way upward from his job as a law writer to his current apprenticeship. The fact that he has also sought out additional work working on the encyclopedia likewise points to his determination. Finally, Traddles's blunt admission that he has "no invention" suggests that he has a good grasp of his strengths and weaknesses, and therefore of his vocation.
Traddles also reveals that he is engaged to a curate's daughter, whom he takes walking trips to see. They cannot currently afford to marry, but Traddles is confident that his fiancée would wait for him for years. In the meantime, he says, they have begun to plan for their eventual home together, and he shows David a flower pot and a side table he has collected for this purpose. Traddles acknowledges that furnishing a house requires much more than he currently has, but he remains content to "wait and hope!"
In David Copperfield, marriage isn't something to take lightly, even setting aside the question of finding an appropriate partner. The expense of maintaining a middle-class household—complete with pleasant but unnecessary items like the flower pot—means that a man must be relatively well established in his career before he can start a family.
Traddles continues to talk about his circumstances, and eventually mentions that his downstairs neighbors (and landlords) are none other than the Micawbers. David begs Traddles to invite Mr. Micawber in, and Mr. Micawber appears, looking and acting much the same as ever. Mr. Micawber answers David's questions about his family's health (all are well) before recognizing him, at which point he greets him delightedly and calls for Mrs. Micawber to join them.
The Micawbers' reappearance at this point in the narrative is not a good omen. Both David and Traddles are just beginning to establish themselves in their careers and work towards financial security, and the Mr. Micawber's ongoing struggles are a reminder of everything that can go wrong.
While they wait for Mrs. Micawber, Mr. Micawber asks David about Doctor Strong and reminisces about their last meeting in Canterbury. He then reminds David (at great length), that he has been prone throughout his life to "periods […] when it has been requisite that [he] should pause, until certain expected events should turn up." This, he says, is one of those times.
Mr. Micawber, as always, is experiencing financial difficulties but confident that he will soon be on the path to success. However, coming on the heels of Traddles's account of his circumstances, Micawber's situation is a reminder of the limits of upward mobility.
Throughout Mr. Micawber's speech, David can hear Mrs. Micawber hastily washing up next door. When she finally comes to Traddles's room and sees David, she faints, and Mr. Micawber has to fetch water to revive her. She reports that the children are well, but seems alarmed when Mr. Micawber invites David to dinner. Guessing that there is not enough food to go around, David instead invites Traddles and the Micawbers to dine with him sometime and then leaves. Mr. Micawber accompanies him to the end of the street, explaining that he is currently involved in the corn business (though he is not being paid) and confirming that Mrs. Micawber is pregnant. He then leaves David, saying that while Mrs. Micawber's relatives may disapprove of her pregnancy, he scorns their opinion.
Presumably, Mrs. Micawber's family disapproves of her pregnancy on the grounds that the couple cannot support more children than they already have (and, perhaps, have brought about their own financial difficulties by having too many children). This was commonly cited as a cause of poverty in the nineteenth century, and it underscores the differences between the Micawbers and Traddles and his fiancée, who are planning ahead for their family's future.