The Shadow is a collection of serialized dramas, originally in 1930s pulp novels, and then in a wide variety of media. Details of the title character have varied across various media. But The Shadow is generally a crime-fighter who works alone instead of with the police. He usually has psychic powers. He poses as a "wealthy, young man about town". The Shadow is one of the most famous adventure heroes of the twentieth century. He has been featured on the radio, in a long-running pulp magazine series, in comic books, comic strips, television, serials, video games, and at least five motion pictures. The radio drama is well-remembered for those episodes voiced by Orson Welles.
The Shadow first appeared on July 31, 1930, as the mysterious narrator of the Street and Smith radio program Detective Story Hour. After gaining popularity among the show's listeners, the narrator became the star of The Shadow Magazine on April 1, 1931, a pulp series created and primarily written by Gibson.
On September 26, 1937, The Shadow radio drama began with the story "The Deathhouse Rescue," in which The Shadow was characterized as having "the power to cloud men's minds so they cannot see him." As in the magazine stories, The Shadow was not given the literal ability to become invisible.
The introduction from The Shadow radio program "Who knows what evil lurks in the hearts of men? The Shadow knows!" was spoken by actor Frank Readick Jr.. American English speakers often have heard of this phrase, even if they have never listened to the radio show. These words were accompanied by an ominous laugh and a musical theme, Camille Saint-Saëns' Le Rouet d'Omphale ("Omphale's Spinning Wheel", composed in 1872). At the end of each episode The Shadow reminded listeners that, "The weed of crime bears bitter fruit. Crime does not pay... The Shadow knows!"
- Stedman, Raymond William (1977). Serials: Suspense and Drama By Installment. University of Oklahoma Press. p. 154. ISBN 978-0806116952.
- Vincent Terrace, Radio Program Openings and Closings, 1931-1972 (Jefferson, NC: McFarlane and Company, 2011), p. 210
- "The Shadow: A Short Radio History". Retrieved 15 July 2015.