Leah Kleschna has been a thief all her life. However, an encounter with a man she intends to rob makes her question her life's course. The film is lost.

The film hinges on the love triangle between a young aristocratic lady on the run (Cleonie, played by Hazel Terry), the murderous Varennes, Citizen-Deputy of the Revolution who saves her by disguising her as his nephew (Nils Asther) and finally the Marquis of Corbal of the film's title, played by Hugh Sinclair.

Courtenay John Dayre is drugged by a jealous spy on the night before his loveless marriage to Anthea. His twin, John Courtenay Dayre, reluctantly agrees to impersonate his brother at the wedding, only to discover a genuine affection for his accidental wife. Meanwhile, Courtenay begins to understand the price of things when he realises that his affair has allowed a valuable military secret to be stolen.