The Taste of Night by Vicki Pettersson

Equal parts Light and Shadow, Joanna Archer must fulfill a destiny she never wanted. Once a photographer and heiress to a casino fortune, she is now dedicated to the cause of good . . . but susceptible to the seductions of evil.

A deadly virus is descending on Las Vegas—a terrifying plague unleashed by the powerful overlord of Zodiac’s dark side: Joanna’s father. Chaos and panic grip Sin City as agents of Light fall prey to the terrifying epidemic. Death reigns supreme—and Joanna stands at dead center of an epic and terrible war long foretold, the last hope of a damned world.

But first she must somehow conquer the malevolence that grows all around her . . . and within.