The Scarlet Pimpernel (2016)

At the heart of the French Revolution, effete aristocrat Sir Percy Blakeney (Leslie Howard) is secretly the Scarlet Pimpernel, leading an underground group dedicated to freeing nobles from the brutal Robespierre. Blakeney plays his part so well that even his own wife, Marguerite (Merle Oberon), doesn't suspect him. Robespierre's agent, Chauvelin (Raymond Massey), learns that Marguerite's brother is one of the Pimpernel's group, and she begins working unknowingly to destroy her own husband.