A body pulled from the Thames is identified as young John Harmon, heir to a fortune made in dust-contracting (a lucrative 19th century recycling business). Bella Wilfer, his wife-to-be by terms of old Harmon's will, goes into mourning though she has never met her fiancé. Bella is adopted by Mr. and Mrs. Boffin, inheritors of the dust business in default of young Harmon. The Boffins also hire a very capable but mysterious young man as secretary, John Rokesmith, whose keen interest in Bella holds the secret to his true identity.
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. As their rivalry gets out of hand, Lizzie flees. Meanwhile, the once-kindly Mr. Boffin has become a tyrant to Rokesmith, who evokes the sympathy of the formerly haughty Bella.
Two low-life characters sifting through the dust mountain have found an alternate will from old Harmon, which they plan to use to blackmail Mr. Boffin.
Rokesmith and Bella have secretly married, without Bella realizing her husband is actually John Harmon, her original fiancé, about to claim his dust fortune from the Boffins, who for their part 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.
This documentary takes a look on how the River Thames was paramount to Charles Dickens novel 'Our Mutual Friend'.
