Daemon's Mark (Nocturne City Series #5)

When the Dubois investigation turns up an unexpected connection to the Russian mob, Luna finds herself heading down a terrifying path of no return. Soon she is held captive by the very evil she hunts—one that reaches far across the borders of Nocturne City to the seedy brothels of Europe and beyond. Now, with street smarts, seduction, and a sixth-sense for danger as her only weapons, Luna will enlist the help of her former lover Dmitri—who has his own reasons for bringing down this crime ring—and risk it all in the ultimate showdown.