See Succubus

Desdemona Cross is good at keeping secrets.

To begin with, she works as a researcher for the Order, a secret society that uses any means necessary to protect human society from the seething underworld of the supernatural that preys on them every night.

But she keeps secrets from them too: specifically, that she's not completely human herself, a lie for which the Order would kill her if they knew.

When Dez transfers to the New York City branch, she becomes entangled in an unsettling series of attacks on supernatural succubus prostitutes, meets Lucius, a seductive supernatural gangster, and Adrael, his shadowy second-in-command, who threatens to expose her in more ways than one.