El Dorado, by Baroness Orczy is a sequel book to the classic adventure tale, The Scarlet Pimpernel. It was first published in 1913. The novel is notable in that it is the partial basis for most of the film treatments of the original book. (Summary from wikipedia) Series: 1: The Scarlet Pimpernel 2: I Will Repay 2.5: The League of the Scarlet Pimpernel 3: The Elusive Pimpernel 4: El Dorado: Further Adventures of the Scarlet Pimpernel 5: Lord Tony's Wife 6: The Triumph of the Scarlet Pimpernel 7: Sir Percy Hits Back Prequel: The Laughing Cavalier