Silas Marner is a member of a small Christian congregation in Lantern Yard who is accused of stealing the congregation's funds while sitting with a very ill elder of the group. Two clues are given against him: a pocket-knife and the discovery of the bag formerly containing the money in his own house. Silas says that he last used the knife to cut some string for his friend William, who leads the campaign against him. Silas is proclaimed guilty and the woman he was to marry casts him off, and later marries William. With his life shattered and his heart broken, he leaves Lantern Yard.
Marner then settles near the village of Raveloe, where he lives as a recluse who exists only for work and his precious hoard of money until that money is stolen by Dunstan Cass, a dissolute younger son of Squire Cass, the town's leading landowner. The loss of his gold drives Silas into a deep gloom, although a number of the villagers endeavour to help him.
Soon, however, an orphaned child comes to Raveloe. She was not known by the people there, but she is really the child of Godfrey Cass, the eldest son of the local squire. Her mother, Molly, is secretly married to Godfrey, but is also of low birth and addicted to opium. On a winter's night, Molly tries to make her way into town with the child to prove that she is Godfrey's wife and ruin him. On the way she takes opium, becomes disoriented and sits down to rest amid the snow, child in arm. Her child wanders from her mother's still body into Silas' house. Upon discovering the child, Silas follows her tracks in the snow and discovers Molly - a woman unfamiliar to him - dead. Silas decides to keep the child and names her Eppie, after his deceased mother and sister, Hephzibah. Eppie changes his life completely. Symbolically, Silas loses his material gold to theft only to have it replaced by the golden-haired Eppie. Godfrey Cass is now free to marry his new love, Nancy, concealing his first marriage from her. Eppie grows up to be the pride of the town and to have a very strong bond with Silas, who through her has found inclusion in the town. Later in the book, Dunstan Cass is found at the bottom of the pond in front of Silas's house with his gold and it is restored to Silas. Godfrey confesses to his wife, Nancy, that the dead woman was his first wife and that Eppie is his child. The couple, who are childless, go to Silas and reveal this to him, asking that Silas give Eppie up to their care. However, the decision falls to Eppie, who has no desire to be raised as a gentleman's daughter if it means forsaking Silas. At the end, Eppie marries a local boy, Aaron, son of Dolly Winthrop, and both of them move into Silas' newly enlarged house, courtesy of Godfrey.