Throughout the day the city lives and works, but when the last character of morning stage leaves, the true inside of London comes out. Charles Dickens
That means everything known in literature as “London of Oliver Twist”; all the “miserable depravity”, all the poverty and deprivation which average people of London slums have to suffer. A provincial girl having come to London one bright morning is a “drunken prostitute” at night.
Charles Dickens
The most famous novel about dark side of London is, undoubtly, “Oliver Twist”, which considered being one of the most significant works, standing in the same row with “David Copperfield” & “Dombey & Son”.
This work Dickens himself considered to be following the tradition of William Hogarth, a prominent English artist of the XVIII century (1697-1764), the first who portrayed life of the poorest layers of the English society.
With a serious theme, to expose the abuse and corruption suffered by children, this work is nevertheless full of humour, but of a satirical kind. The orphan Oliver Twist manages to survive the worst that the authorities and criminal fraternity put him through. The scene of Oliver's plea in the workhouse for more to eat is familiar to countless millions, even to those who have never read the book. The scene gave birth to a nominal of Oliver Twist, which means someone who is not satisfied with his share. Another nominal originating from this novel is a nickname of Artful Dodger, one of Fagin’s true pupils.

Charles Dickens
The characters are more complicated: they include all types of vices but they can also vary from quite negative to sympathetic & even positive & drawing compassion. They are Charley Bates (the only one from Fagin’s criminal company who managed to escape vengeance, maybe because he was the most innocent of all) & Nancy, the fallen angel, the saver of Oliver.
Charles Dickens
But as far as it is criminal night London good falls the victim of evil.