In the midst of the chaos and violence of the French Revolution, an English aristocrat becomes a mystery in London. Known only by his nickname, this daring hero leads a double life: by night, he transforms into a fearless savior of French nobles condemned to death, while during the day he is the carefree Sir Percy Blakeney, a man of high society who seems more interested in parties than in the political troubles of Europe.
As the echoes of the guillotine resonate in Paris, the cunning Blakeney plans audacious rescues, using his wit and cleverness to outsmart the watchful revolutionary Chauvelin, who is determined to capture him. However, the situation complicates when Blakeney's love, Marguerite St. Just, becomes a pawn in the deadly game between the two men.
Caught between his love for Marguerite and his duty to protect the persecuted, Sir Percy must use all his resources to prevent the guillotine from claiming more lives. The film blends romance and tension, with a touch of English humor, as the notes of an intrigue plot intertwine; loyalty, sacrifice, and honor are put to the test in an exhilarating confrontation where life and death hang by a thread, and cunning may be the only salvation in times of desperation.