Middlemarch is a panoramic novel of English provincial life set around 1830, in the years of agitation before the first Reform Bill. Its title is the name of a market town, and its real subject is the gap between the large things people mean to do and the ordinary conditions in which they must do them. A Prelude frames the whole book through Saint Theresa, asking what becomes of an ardent, idealistic nature born into a time and place that offer it no great task.
Its central figure is Dorothea Brooke, a clever, intense young woman who longs to give her life to some noble purpose and mistakes the pedantic, much older clergyman-scholar Edward Casaubon for a great mind she can serve. She marries him, and the marriage curdles into quiet desolation: his vast research, a never-finished Key to all Mythologies, turns out to be a labyrinth leading nowhere, and his jealous coldness shuts her out. Into this disappointment comes his young cousin Will Ladislaw, whom Casaubon's will tries to keep from her even after his death.
Running alongside Dorothea is Tertius Lydgate, a gifted, ambitious doctor who comes to Middlemarch meaning to advance medical science and reform local practice. He has, the narrator says, fine intentions spotted with commonness, and he marries the beautiful Rosamond Vincy expecting an ornament to his life. Instead her soft, inflexible will and their mounting debts gradually cage him, and his great research ambitions collapse into a comfortable, ordinary practice he privately counts a failure.
Around these two marriages the town's other lives interlock. Rosamond's brother Fred Vincy must give up idle gentlemanly hopes to earn the steady, loving Mary Garth. The pious banker Bulstrode is exposed when a man from his disreputable past, Raffles, arrives to blackmail him, and his fall pulls Lydgate down by association. Reform, religion, money, and reputation move through the whole community, and the narrator keeps reminding us that she is tracing one particular web of connected lots rather than any single hero's story.
The Finale follows the characters into their after-years. Fred and Mary make a solid, modest happiness; Lydgate gains income but never does what he meant to do and dies feeling he failed; Dorothea, against her family's judgment, gives up wealth and position to marry Ladislaw and lives a life of unrecorded good. Eliot refuses a triumphant ending and offers instead a famous consolation: that the growing good of the world depends partly on people who lived faithfully a hidden life and lie in unvisited tombs.