It’s the dawn of the 19th century and a masked man is attacking women of the night in London. Just as this fiend hides his secret identity, Irish singer Rose O’Keefe must conceal her feelings for the Marquess of Tannerton’s secretary, Jameson Flynn. While Flynn may wish to be with his siren, the Marquess has already set his eyes on having her, if only to prevent her from falling into the clutches of the despicable Earl of Greythorne. Never mind the love triangle; can Rose manage to survive the harsh streets of London, or will she soon be singing her swan song?