The French revolution was a revolt against aristocracy, or the rich nobles.
Sergesnt Grospierre, in charge of the North gate, was to be beheaded for allowing a noble family to escape.
Sergeant Bibot at the west gate was very clever. He could recognize a person, even in the most perfect disguise.
Yet, a mysterious englishman kept saving nobles. He sends a piece of paper, signed with a design of a red flower, called the Scarlet Pimpernel. A few hours later, they would get to know that members of the aristocracy has escaped.
Sergeant Bibot narrated the story of Sergeant Grospierre, of how he thought himself clever and check a single barrel and let a noble family escape.
One day, an old woman came to the gate. When Sergeant Bibot asked to open the cover of the cart, she said "It's my son. He has been infected by Smallpox." By the first mention of the deadly disease, Sergeant Bibot strode back. A few hours later, the captain of the guard came to inform the old woman was scarlet pimpernel and in the cart was a noble family.