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!"