In 1792 during the Reign of Terror of the French Revolution, a mysterious English nobleman known only as The Scarlet Pimpernel (a humble wayside flower) snatches French aristocrats from the jaws of the guillotine while posing as the wealthy but foppish and seemingly empty-headed Sir Percival Blakeney. Percy marries the beautiful French actress Marguerite St. Just, but her previous relationship with Robespierre's agent Paul Chauvelin may endanger the Pimpernel's plans to save the young Dauphin, eldest son of the former King of France.