Young Martin Chuzzlewit was raised by his grandfather, also named Martin Chuzzlewit. The senior Martin, a very wealthy man, has been long convinced that everyone around him is after his money, and so he took the precau...展开tion, years before the book begins, of raising an orphaned girl, Mary, to be his nursemaid, with the understanding that she would be very well taken care of as long as he lived, and be thrown out onto the streets, penniless, after he dies. She would therefore have great motivation to care for his well-being and safeguard him from harm, in contrast to his relatives, who want him to die. However, his grandson and heir, Martin, falls in love with Mary and wishes to marry her, ruining the senior Martin's plans to keep her disinterested in his fortune. He demands his grandson give up the engagement, but he refuses and becomes disinherited from his grandfather. He decides to sign on as an apprentice to Mr. Pecksniff, a talentless, greedy, pseudo-pious poseur who periodically takes in students to teach them architecture, while actually teaching them nothing, treating them badly, and living grandly off their tuition. He has two vain, spoiled, mean-spirited and pseudo-pious daughters, Mercy (Merry) and Charity (Cherry). Unbeknownst to young Martin, Mr. Pecksniff, who is a relative of Chuzzlewit's, has taken the grandson on in order to establish closer ties with the wealthy grandfather, thinking that the grandfather's gratitude will give Pecksniff a prominent place in the will. While with the Pecksniffs, the younger Martin meets and befriends Tom Pinch, who is in some ways the true protagonist of the book. He is a gentle, kind-hearted soul whose late grandmother gave Pecksniff all she had, believing Pecksniff would make a grand architect and gentleman of him. Pinch is so virtuous that he is incapable of believing any of the bad things others tell him of Pecksniff, and always defends him vociferously. He also has a sister who is a governess in London. He works for Pecksniff for exploitatively low wages, all the while believing that he is the unworthy recipient of Pecksniff's charity. We briefly meet John Westlock, a former student of Pecksniff's who sees the value of Pinch and the evil of Pecksniff, and parts ways from the household as the book is beginning.
When Grandfather Chuzzlewit hears of his grandson's new life, he requires Mr. Pecksniff to kick the penniless young Martin to the street. The senior Martin moves in with Mr. Pecksniff and slowly appears to fall under his complete control. During this sojourn, Pinch falls in love with Mary, but does not declare his love, knowing of her attachment to the young Martin.
Anthony and Jonas ChuzzlewitOne of Martin senior's greedy relatives is his brother, Anthony Chuzzlewit, who is in business with his son, Jonas. While somewhat affluent themselves, they live miserly, cruel lives, with Jonas constantly berating his father, eager for the old man to die so he can get control of his inheritance. Anthony dies abruptly and under suspicious circumstances, leaving his wealth to Jonas. Jonas then woos Charity Pecksniff, who is very flattered, while insulting and arguing constantly with Mercy, whom he refers to as "the other one," instead of by name. He then abruptly and cruelly declares to Seth Pecksniff that he wants to marry Mercy, and jilts a furious Charity. During their courtship, Mercy continues to tease and abuse him verbally, enjoying her power over him, to which he responds affably, muttering that he will get his revenge once they are married. This indeed happens, and he seriously physically and emotionally abuses Mercy once the marriage has taken place. Her personality changes from that of a giggly, flighty girl to an oppressed and frightened woman. Charity delights in Mercy's pain.
Jonas, meanwhile, becomes entangled with the unscrupulous Montague Tigg and becomes financially involved in his pyramid scheme-like insurance scam. Introduced at the beginning of the book as Tigg Montague, a dirty, petty thief and hanger-on, he transforms himself into a seemingly fine man of quality through dressing better and renting a nice office and other false manifestations of a success. This facade is enough to convince investors that he must be an important businessman from whom they may greatly profit.
Tom PinchWhile this is occurring, Tom Pinch, after years of devoted service, finds out the true nature of Mr. Pecksniff's character when he mistreats Mary, and leaves him at last. He goes to London to seek employment and rescues his governess sister Ruth, who he discovers has been severely mistreated by the cruel family who has been employing her, and they set up housekeeping together. He renews his friendship with John Westlock, who has recently come into an inheritance. Pinch quickly receives an ideal job from a mysterious employer, with the help of an equally mysterious Mr. Fips.
Young Martin, meanwhile, has fallen in with Mark Tapley, a kind man from the inn in the town where Pecksniff lives. Mark, a satirical character, is always affable and cheerful, which he decides does not reflect well on him because he is always in happy circumstances. He decides he must test his cheerfulness by seeing if he can maintain it in the worst circumstances possible. To this end, he decides to accompany young Martin Chuzzlewit as his unpaid servant (indeed, he uses up his life savings paying for things for Martin) as he makes his way to the United States to seek his fortune. The men travel to America, make many humorous observations about the generally low, degraded or silly character of the American people, and then attempt to start new lives in a swampy, disease-filled settlement named Eden by the corrupt hucksters who sell him his land. Mark and Martin both nearly die in Eden of malaria. The experience changes Martin's selfish character and they return to England after the experience, where he is resolved to return penitently to his grandfather, humbled and changed. But his grandfather is now apparently under Mr. Pecksniff's control and rejects him. Mr. Pecksniff also becomes financially involved in Montague Tigg's insurance scam through the intervention of Jonas, who is being blackmailed by Tigg, who has some kind of information on Jonas. The information is not revealed until the end of the book, but it is implied that he has evidence that Jonas killed his father.
John Westlock and Ruth PinchOn his return, Young Martin is reunited with Tom Pinch. At this point, Jonas Chuzzlewit murders Tigg Montague when the insurance scam is failing, in order to prevent him from revealing the information he's been using as blackmail. Meanwhile, Tom Pinch discovers that his mysterious benefactor/employer is old Martin Chuzzlewit. The elder Martin reveals that when he saw the ends to which greed would take one (in the case of Jonas and Anthony), he decided to sit back and pretend to be in doddering thrall to Pecksniff, while he carefully planned to give everyone enough rope to hang themselves with. He soon realizes the evils of Pecksniff and the good of Pinch. Together, the group confronts Mr. Pecksniff with their knowledge of his true character. Mr. Nadgett leads the group to the discovery of Jonas as the murderer of Montague. They also find out from Anthony's devoted employee Chuffey that Jonas did not murder his father, but did plan to murder him, and in fact thought he had (with poison), when really the father died of a broken heart when he realized his own son wanted him dead. Martin also reveals that he was angry at his grandson for becoming engaged to Mary because he had all along planned to arrange that particular match, and felt his glory had been thwarted by them deciding on the plan themselves, instead. He realizes the folly of that opinion, and Martin and his grandfather are reconciled. Martin and Mary get married, Ruth Pinch gets married to John Westlock, and the other characters generally get what they deserve, good or bad. However, Tom Pinch remains in unrequited, undeclared love with Mary for the rest of his life, never marrying, and always being a warm companion to Mary and Martin and to Ruth and John. The goodness of his heart is such that he is glad to see his loved ones happy, even though he does not partake of this joy himself.