A body pulled from the Thames is identified as young John Harmon, heir to a fortune made in dust-contracting. Bella Wilfer, his wife-to-be by terms of old Harmon's will, goes into mourning though she has never met her fiancé.

Lizzie Hexam, daughter of the corpse robber who found young Harmon's alleged body, is being courted by two desperate characters: Eugene Wrayburn, a dissolute barrister, and Bradley Headstone, a mentally-deranged schoolmaster.

Harmon is planning to claim his dust fortune from the Boffins, who have been playing villains to test Bella's true character. Meanwhile, Eugene has a brush with death via Headstone and decides to do the honorable thing with Lizzie.

As the rivalry over who will take Lizzie's hand in marriage intensifies, Lizzie flees. Meanwhile, the once-kindly Mr. Boffin has become a tyrant to Rokesmith, who evokes the sympathy of the formerly haughty Bella.