A rich widow adopts the two-year-old daughter of a former servant and raises her with her own daughter who is the same age. For some reason, the widow will not tell the girls which one is adopted. One of them is sent to live with a sister and therefore thinks that she must be the poor adopted one. As one may imagine, the story revolves around this scenario for a while until it is revealed that she is NOT the adopted one. The author paints a faithful picture of London slum life without being offensive and the plot is quite intricate and loaded with entertaining characters much like Dickens.