Middlemarch centres on the lives of residents of Middlemarch, a fictitious Midlands town, from 1829 onwards – the years up to the 1832 Reform Act. The narrative may be considered to consist of four plots with unequal emphasis:[17] the life of Dorothea Brooke, the career of Tertius Lydgate, the courtship of Mary Garth by Fred Vincy, and the disgrace of Nicholas Bulstrode. The two main plots are those of Dorothea and Lydgate.[18] Each plot occurs concurrently, although Bulstrode's is centred on the later chapters.[19]
Dorothea Brooke is a 19-year-old orphan, living with her younger sister, Celia, as a ward of her uncle, Mr Brooke. Dorothea is an especially pious young woman whose hobby involves the renovation of buildings belonging to the tenant farmers, although her uncle discourages her. Dorothea is courted by Sir James Chettam, a man close to her own age, but she is oblivious to him. She is attracted instead to the Rev. Edward Casaubon, a 45-year-old scholar. Dorothea accepts Casaubon's offer of marriage, despite her sister's misgivings. Chettam is encouraged to turn his attention to Celia, who has developed an interest in him.
Fred and Rosamond Vincy are the eldest children of Middlemarch's town mayor. Having never finished university, Fred is widely seen as a failure and a layabout, but is content because he is the presumed heir of his childless uncle Mr Featherstone, a rich but unpleasant man. Featherstone keeps as a companion a niece of his by marriage, Mary Garth; although she is considered plain, Fred is in love with her and wants to marry her.
Dorothea and Casaubon experience the first tensions in their marriage on their honeymoon in Rome, when Dorothea finds that her husband has no interest in involving her in his intellectual pursuits. She meets Will Ladislaw, Casaubon's much younger disinherited cousin whom he supports financially. Ladislaw begins to feel attracted to Dorothea; she remains oblivious, but the two become friendly.
Fred becomes deeply in debt and finds himself unable to repay what he owes. Having asked Mr Garth, Mary's father, to co-sign the debt, he now tells Garth he must forfeit it. As a result, Mrs Garth's savings from four years of income, held in reserve for the education of her youngest son, are wiped out, as are Mary's savings. Mr Garth thus warns Mary against ever marrying Fred.
Fred comes down with an illness and is treated by Dr Tertius Lydgate, a newly arrived doctor in Middlemarch. Lydgate has modern ideas about medicine and sanitation which draw ire and criticism of many in town. He allies himself with Bulstrode, a wealthy, church-going landowner and developer who wants to build a hospital and clinic that follow Lydgate's philosophy, despite the misgivings of Lydgate's friend, Farebrother, about Bulstrode's integrity. Lydgate also becomes acquainted with Rosamond Vincy, who is beautiful and educated, but shallow and self-absorbed. Seeking to make a good match, she decides to marry Lydgate, who comes from a wealthy family, and uses Fred's sickness as an opportunity to get close to him. Lydgate initially views their relationship as pure flirtation and backs away from Rosamond after discovering that the town considers them practically engaged. However, on seeing her a final time, he breaks his resolution and the two become engaged.
Casaubon arrives back from Rome about the same time, but suffers a heart attack. Lydgate attends him and tells Dorothea it is difficult to pronounce on the nature of Casaubon's illness and chances of recovery: that he may indeed live about 15 years if he takes it easy and ceases his studies, but it is equally possible the disease may develop rapidly, in which case death will be sudden. As Fred recovers, Mr Featherstone falls ill. On his deathbed, he reveals that he has made two wills and tries to get Mary to help him destroy one. Unwilling to be involved in the business, she refuses, and Featherstone dies with both wills still intact. Featherstone's plan had been for £10,000 to go to Fred Vincy, but his estate and fortune instead go to his illegitimate son, Joshua Rigg.
Casaubon, in poor health, has grown suspicious of Dorothea's goodwill to Ladislaw. He tries to make Dorothea promise, if he should die, to forever "avoid doing what I should deprecate, and apply yourself to do what I should desire". She is hesitant to agree, and he dies before she can reply. Casaubon's will is revealed to contain a provision that, if Dorothea marries Ladislaw, she will lose her inheritance. This leads to the general suspicion that Ladislaw and Dorothea are lovers, creating awkwardness between the two. Ladislaw is in love with Dorothea but keeps this secret, having no desire to involve her in scandal or cause her disinheritance. She realizes she has romantic feelings for him, but must suppress them. He remains in Middlemarch, working as a newspaper editor for Mr Brooke, who is mounting a campaign to run for Parliament on a Reform platform.
Lydgate's efforts to please Rosamond soon leave him deeply in debt, and he is forced to seek help from Bulstrode. Meanwhile, Fred Vincy's humiliation at being responsible for Caleb Garth's financial setbacks shocks him into reassessing his life. He resolves to train as a land agent under the forgiving Caleb. He asks Farebrother to plead his case to Mary Garth, not realizing that Farebrother is also in love with her. Farebrother does so, thereby sacrificing his own desires for the sake of Mary, who he realises truly loves Fred and is just waiting for him to find his place in the world.
John Raffles, a mysterious man who knows of Bulstrode's shady past, appears in Middlemarch, intending to blackmail him. In his youth, the church-going Bulstrode engaged in questionable financial dealings; his fortune is founded on his marriage to a wealthy, much older widow. The widow's daughter, who should have inherited her mother's fortune, had run away; Bulstrode located her but failed to disclose this to the widow, so that he inherited the fortune in lieu of her daughter. The widow's daughter had a son, who turns out to be Ladislaw. On grasping their connection, Bulstrode is consumed with guilt and offers Ladislaw a large sum of money, which Ladislaw refuses as being tainted. Bulstrode's terror of public exposure as a hypocrite leads him to hasten the death of the mortally sick Raffles, while lending a large sum to Lydgate, whom Bulstrode had previously refused to bail out of his debt. However, the story of Bulstrode's misdeeds has already spread. Bulstrode's disgrace engulfs Lydgate: knowledge of the loan spreads and he is assumed to be complicit with Bulstrode. Only Dorothea and Farebrother retain any faith in him, but Lydgate and Rosamond are still encouraged to leave Middlemarch by the general opprobrium. Disgraced and reviled, Bulstrode's one consolation is that his wife stands by him as he too faces exile.
When Mr Brooke's election campaign collapses, Ladislaw decides to leave the town and visits Dorothea to say his farewell, but Dorothea has fallen in love with him. She renounces Casaubon's fortune and shocks her family by announcing that she will marry Ladislaw. At the same time, Fred, having been successful in his new career, marries Mary.
The "Finale" details the ultimate fortunes of the main characters. Fred and Mary marry and live contentedly with their three sons. Lydgate operates a successful practice outside Middlemarch and attains a good income, but never finds fulfilment and dies at the age of 50, leaving Rosamond and four children. After he dies, Rosamond marries a wealthy physician. Ladislaw engages in public reform, and Dorothea is content as a wife and mother to their two children. Their son eventually inherits Arthur Brooke's estate.
