"The Mysteries of Paris, illustrated with etchings, Vol. 4" by Eugène Sue is a serial novel published between 1842 and 1843. This groundbreaking work follows the mysterious Rodolphe, secretly a German Grand Duke disguised as a Parisian worker, as he navigates all levels of society to restore justice and aid the downtrodden. Moving through the criminal underworld and aristocratic circles alike, Rodolphe encounters prostitutes, reformed criminals, and the desperate poor in a melodramatic tale that exposed social inequalities and inspired the entire "city mysteries" genre across the Western world. (This is an automatically generated summary.)