This is another sequel to the adventure tale of "The Scarlet Pimpernel." The novel revolves around Yvonne, the daughter of Duc de Kernogan. A young French peasant, Pierre Adet, is incensed at the unjust treatment of the local peasantry and plans a mob attack on the Duc de Kernogan. His plan fails and he is forced to flee Nantes. But the Duc, determined to have justice, has Pierre's father hanged for his son's crime. By the time Adet discovers this, it is too late, and he is driven to seek vengeance on Duc and his daughter. Adet, who is now known as Martin-Roget in England, is posing as a millionaire banker. He plans to marry Yvonne and lure her and the Duc back to Nantes, where they will be executed as ci-devants on the guillotine with the help of Chauvelin.