London, 1817. The Marquess of Tannerton has whatever he needs, but what he truly desires is the company of Rose O'Keefe, the Irish singer who's been captivating hearts at Vauxhall Gardens. While Tannerton's secretary, Flynn, may be proper enough to keep his own interest in the lady from disrupting his employment, the foreboding Lord Greythorne appears to take whatever-and whomever-he wants, whether by money or force. All Rose wishes to do is sing for Flynn, but she may end up using her beautiful voice to cry for his help.
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?