The Nymph and the Senator

From publisher blurb: In Lex Arcana, you are a Custos (warden) of the Cohors Auxiliaria Arcana, sent by the Emperor to the four corners of the world to further the study of arcane lore, investigate forbidden cults, and face the thread posed by dangerous supernatural creatures. The distinguished senator Caius Sempronius Albulus has submitted a shocking request to the Senate: what mystery is hidden behind this absurd and quick demand?