The Scarlet Pimpernel is set in 1792, during the early stages of the French Revolution. Marguerite St. Just, a beautiful French actress, is the wife of wealthy English fop Sir Percy Blakeney, a baronet. Before their marriage, Marguerite took revenge upon the Marquis de St. Cyr, who had ordered her brother to be beaten for his romantic interest in the Marquis' daughter, with the unintended consequence of the Marquis and his sons being sent to the guillotine. When Percy found out, he became estranged from his wife. Marguerite, for her part, became disillusioned with Percy's shallow, dandyish lifestyle.

Meanwhile, the "League of the Scarlet Pimpernel", a secret society of 20 English aristocrats, "one to command, and nineteen to obey", is engaged in rescuing their French counterparts from the daily executions (see Reign of Terror). Their leader, the mysterious Scarlet Pimpernel, takes his nickname from the drawing of a small red flower with which he signs his messages. Despite being the talk of London society, only his followers and possibly the Prince of Wales know the Pimpernel's true identity. Like many others, Marguerite is entranced by the Pimpernel's daring exploits. (summary by Wikipedia)