Paris, September 1793. Louise de Croissy needs permission to take her dangerously ill son Charles-Léon into the country, but revolutionary travel controls make a simple journey impossible. Her young friend Josette Gravier is convinced that only the Scarlet Pimpernel can secure their escape. Carrying information and letters that may expose powerful men, Josette sets out to find a hero whose identity she does not know.
Josette and Maurice Reversac are drawn into the rivalries surrounding Danton and other revolutionary leaders, while Chauvelin attempts to use their movements to uncover Percy’s network. The rescue must protect the child, the messengers and people compromised by the papers they carry. The novel gives unusual prominence to an ordinary young woman’s initiative, showing the Pimpernel’s method as a chain of trust in which apparent chance, disguised allies and carefully timed intervention work together.