Mariette is a lady’s companion and a Nephilim who traffics in magical objects and casual sex. Mony sends her as the bearer of incriminating letters.
She appears at the Grand Hotel de Paris as a visitor carrying letters between Mony and Mony’s contacts. The identity of Culculine is revealed through the letters, among them one from Culculine to Mony: “Mi bello rumano…” (“My handsome Romanian…”). She later reappears as an employee of the train and hotel, the Orient Express. She acts as a go-between for characters in underground Paris.