El Dorado (1913) by Baroness Emma Orczy is a sequel to The Scarlet Pimpernel and one of the most famous books in the series. It is particularly significant because it served as the basis for the 1919 film adaptation of The Scarlet Pimpernel. The novel continues the adventures of Sir Percy Blakeney, the daring English aristocrat who risks his life to rescue victims of the French Revolution's Reign of Terror.