Lucy lives with her father in Southwark. All is well until his gambling losses escalate to the extent where he has to give the house over to a criminal gang, who take over while he and Lucy are allowed to stay living in a room upstairs. One of the gang, the Duke, is a frightening man with one blind eye and one glass eye. He decides to use Lucy as a guide, leading him from house to house. Meanwhile, one of the other tenants of the house threatens to expose the gang's activities, and is found strangled in his room the next morning. The gang manage to point the finger of blame at Lucy's father. Lucy and her friend, Tom, manage to find a way of clearing Lucy's father and getting out of this horrible situation, and all ends happily. BLExciting murder mystery plot with strong period detail and Dickensian characters, set in the early half of the nineteenth century