D'Eon is a member of the Secret Police, working in the shadows to keep the peace within French society. When his sister suddenly turns up floating down a river in a coffin with 'Psalms' written on it, D'Eon is thrown into a deadly struggle with revolutionaries and supernatural forces in order to uncover the truth behind his sister's death. He is loosely based on the historic figure, Chevalier d'Eon.

(Source: Wikipedia)