City mysteries are a 19th-century genre of popular novel, in which characters explore the secret underworlds of cities and uncover corruption and exploitation.
The "mysteries" originated with the wildly successful serial novel The Mysteries of Paris (1842) by Eugène Sue, which had many imitators and lent the genre its name. The novels were usually first serialized in newspapers, and were (like their less-respectable contemporaries the penny dreadfuls) controversial for their frank depiction of violence and sexual deviancy. They were broadly popular in both Europe and the United States, where The Quaker City (1844) held the title of fiction bestseller until unseated by Uncle Tom's Cabin.
Prominent examples include: