Succubus Blues by Richelle Mead

A wisecracking succubus living in Seattle tries to maintain a low-profile day job at a used bookstore while secretly feeding on human desire, but her life is upended when she falls for a mortal man and becomes entangled in a dangerous mix of murder, demonic politics and the cost of giving into real emotion; torn between duty to her infernal employers and the chance at something like redemption, she must navigate betrayal, attraction and the consequences of choosing a human heart over her own nature.

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