The Mysteries of London in 4 volumes is a "penny blood" classic. There are many plots in the story, but the overarching purpose is to reveal different facets of life in London, from its seedy underbelly to its over-indulgent and corrupt aristocrats. The Mysteries of London are considered to be among the seminal works of the Victorian "urban mysteries" genre, a style of sensational fiction which adapted elements of Gothic novels – with their haunted castles, innocent noble damsels in distress and nefarious villains – to produce stories which instead emphasized the poverty, crime, and violence of a great metropolis, complete with detailed and often sympathetic descriptions of the lives of lower-class lawbreakers and extensive glossaries of thieves' cant, all interwoven with a frank sexuality not usually found in popular fiction of the time.

George W. M. Reynolds (1814-1879) was a British fiction writer and journalist. He began residence in Paris in 1834, where he started a daily English newspaper. The venture failed, and Reynolds returned bankrupt to England in 1836. His best-known work was the long-running serial The Mysteries of London