Silas is a weaver living in a manufacturing city in the north of England. He and his friends are Dissenters, Christians who don't belong to the state-sponsored Anglican Church that was (and is) dominant in England. Things are good. He's got a best friend named William Dane, a best girl named Sarah, and the only minor issue is that he occasionally spaces out—like, really spaces out, to the point that he doesn't know what's going on around him.
And then he's accused of theft. The group kicks him out, and Silas makes his way south to the Midlands, where he sets up his loom and settles down in the village of Raveloe. Business is good, but the villagers think he's a weird loner. For fifteen whole years, he weaves and holds nightly sessions with his growing hoard of money.
Meanwhile, things aren't going well for Raveloe's wealthy family up at the Red House. The head of the family, old Mr. Cass, is a jerk, and he's got a jerky younger son, Dunstan. His older son, Godfrey is secretly married to the opium-addled Molly. This is depressing to Godfrey, because these are pre-regular divorce days, and he's got his eye on another girl, Nancy Lammeter.
When the main action of the story opens, Dunstan convinces Godfrey to sell his horse to pay a debt, and even offers to sell it for him. Big mistake, Godfrey. Before getting the money, Dunstan takes the horse off hunting, but he makes a stupid move and the horse ends up dead. As Dustan is walking home, he spies Silas's cottage and has the bright idea to steal the money everyone suspects Silas has.
Silas, who can't catch a break and knows it, promptly sinks into depression. He's depressed all through Christmas, and then New Year's arrives. Up at the Red House, Mr. Cass is giving his big annual party. Godfrey recklessly flirts with Nancy. Dunstan is nowhere to be found, and hasn't been for a while.
Down near the Stone-Pits by Silas's cottage, Molly trudges along the snow-covered road carrying a child. She takes some opium (dumb), sits down under a bush (dumber), and falls asleep (really, really dumb, but also sad). The child wakes up and toddles off, accidentally—or miraculously?—deciding to cuddle up in front of Silas's hearth.
Silas refuses to let anyone take the child: she's his replacement for the gold. Cue the life-changing montage. Silas takes advice from his neighbors, has her baptized, and stops hoarding for the sake of hoarding. The next sixteen years pass in a haze of neighborly good-feeling and childish hijinks.
When Part Two opens, we meet a grown-up Eppie. She's eighteen, adorable, and everyone loves her, most especially Dolly Winthrop's son Aaron. But all is not well up at the Red House: Godfrey and Nancy are childless. One day, Godfrey comes to give Nancy some news: first, they've found Dunstan. He was lying drowned at the bottom of the quarry, which has been drained as a nearby landowner improves his land. Second, Dunstan had stolen Silas's money, and the money has now been returned to Silas. Third, Eppie is Godfrey's child.
Nancy and Godfrey offer to adopt Eppie, but she refuses. She loves Silas, she loves the villagers, and she's going to marry Aaron. The novel ends with a wedding. As Aaron, Silas, and Eppie—who would be unbearably annoying, if she weren't fictional—enter their little cottage, Eppie sighs with happiness.