This savage, biting commentary on bourgeois capitalism and modern morality is set in Victorian London, however Capital Playhouse gives it a new treatment mixing in modern and 1920's styles as well.

The bitter tale is told of the predatory outlaw known as Mack the Knife who secretly marries the daughter of Soho's underworld boss, Peacham, but is soon betrayed by his sinister in-laws and sent to prison. The plot twists between Mack's old friendship with the chief of police and his feud with Peacham.