Ace of Shadows by Amanda Foody

Enne Salta was raised as a proper young lady, and no lady would willingly visit New Reynes, the so-called City of Sin. But when her mother goes missing, Enne must leave her finishing school—and her reputation—behind to follow her mother’s trail to the city where no one survives uncorrupted.

Frightened and alone, Enne has only one lead: the name Levi Glaisyer. Unfortunately, Levi is not the gentleman she expected—he’s a street lord and a con man. Levi is also only one payment away from cleaning up a rapidly unraveling investment scam, so he doesn’t have time to investigate a woman leading a dangerous double life. Enne’s offer of compensation, however, could be the solution to all his problems… Read more.