Early one morning, Mark Tapley arrives at Tom Pinch’s home, accompanied by Martin. Tom is overjoyed to see his old friends back from America. As they catch up on each other’s news, Mark takes over the role as servant until Tom warns him that if he will not sit down, he will swear at him. Tom suggests to Martin that his friend John Westlock might have some advice for him, so the men travel to London. John welcomes them, but explains that he has another visitor, whose business has some connection with Martin. Tom and Mark leave, and Mark announces to Tom that he is planning on marrying Mrs. Lupin. Tom is overjoyed and chides Mark for not marrying her long before.

Martin is introduced by John to Mr. Lewsome, John’s friend who had been so recently ill. Lewsome explains that he was an assistant surgeon and had known Jonas Chuzzlewit, having played cards with him often. Jonas had complained to Lewsome about the selfishness of his father, Anthony, and his increasing decrepitude. In exchange for forgiveness for some gambling debts, Lewsome had given Jonas some slow-acting poison, knowing that Jonas planned to mix it with his father’s cough medicine. Lewsome writes out his confession of being implicit in the murder of Anthony Chuzzlewit. Martin and John decide they must verify this with Mr. Chuffey, still in the care of Mrs. Gamp, since he had known Anthony so well.

Mr. Sweedlepipe tells Mrs. Gamp that he has heard that Bailey is dead and that Montague Tigg (or Tigg Montague) is missing. Mrs. Gamp’s partner, Betsey Prig, comes to visit. They begin drinking and soon fall to arguing about Mrs. Gamp’s supposed friend, Mrs. Harris, who Mrs. Prig does not believe exists. The two women fall out and Mrs. Prig leaves. Martin and John arrive but see that Mrs. Gamp is too overcome with alcohol to be much good. They urge her to find another partner to help take care of Mr. Chuffey and resolve to return later to talk to her about Lewsome’s information.

Martin comes to see Tom and announces that he is breaking off their friendship. Tom is confused, not knowing what he has done to offend Martin, but Martin will not say what it is, though he hints that it has to do with Tom’s employer (whose identity Tom still does not know). Upset, Ruth tells Tom that she knows he is in love with Mary Graham. Tom confesses it but that he never entertained any hope that she would love him. The next day, Tom goes to work and discovers that his employer is none other than old Martin Chuzzlewit. He explains that he has acted secretly, not only with Tom but also with Pecksniff as he lived in his home. He promises Tom that all will soon be revealed.