A rich dust contractor allows his son John Harmon to return from exile as long as he marries Bella Wilfer. A body found in the river is believed to be Harmon but it is in fact a shipmate who had his papers. Harmon takes the name John Rokesmith and becomes the secretary to Mr. Boffin, eventually inheriting his property.

This was Dicken's last completed novel (The Mystery of Edwin Drood was left unfinished), his 14th, and combines psychology with social comment, having the strong symbolism of linking dirt with money and thus showing the corruption that wealth can bring.