Using a disguise as a dandified English nobleman, Sir Percy Blakeney goes undercover, pulling of daring missions, in order to rescue innocent French nobles from the guillotine of the French Revolution. Blakeney, along with his wife, Marguerite St. Just, her brother Armand St. Just, and his second in command, Sir Andrew Ffoulkes, weave their way through a complex plot of love, lies, misunderstandings, betrayals and the threat of betrayals to rescue the heir to the French monarchy.